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  1. O - Ounce (of drugs)
  2. O RLY - Oh Really
  3. O&O - Over and Out
  4. O) - Clown nose smiley face
  5. O-O - Shock
  6. O.O - Very valid, pithy, suiccnct, and on point. WD.
  7. O/ - High five
  8. O/P - Out of print
  9. O/\O - High five
  10. O7 - Salute
  11. O:) - Innocent, angelic
  12. O:-) - Innocent, angelic
  13. OA - Over acting
  14. OAN - On Another Note
  15. OAO - Over And Out
  16. OAOO - One And Only One
  17. OAP - Old Age Pensioner
  18. OAR - On a roll
  19. OASRN - On a site right now
  20. OATUS - On A Totally Unrelated Subject
  21. OAUS - On An Unrelated Subject
  22. OB - Oh brother
  23. OBBY - Good game
  24. OBE - Overcome By Events
  25. OBEX - Object Exchange
  26. OBGYN - Gynecologist (OBstetrics and GYNecology)
  27. OBHWF - One Big Happy Weasely Family
  28. OBKB - Okay, bye bye
  29. OBO - or best offer
  30. OBQ - Oh, Be Quiet
  31. OBS - Obviously
  32. OBTW - Oh, by the way
  33. OBTWIAU - Oh by the way I adore you
  34. OBTWIAVBP - OBligatory The World Is A Very Big Place
  35. OBV - Obviously
  36. OBVI - Obviously
  37. OBVS - Obviously
  38. OBVY - Obviously
  39. OBVZ - Obviously
  40. OBX - Old Battle Axe
  41. OC - Own Character
  42. OCD - Obsessive Compulsive Disorder
  43. OCH - Oh (Scottish)
  44. OCIA - Of Course I Am
  45. OCN - Of Course Not
  46. OCO - Oh, Come On
  47. OCR - Optical Character Recognition
  48. OCT - On Company Time
  49. OD - Oh Dear
  50. ODAAT - One Day At A Time
  51. ODF - Own Damn Fault
  52. ODG - Oh Dear God
  53. ODL - Oh Dear Lord
  54. ODST - Orbital Drop Shock Trooper (Gaming)
  55. ODT - On Dis Ting
  56. ODTAA - One Damn Thing After Another
  57. OED - Oxford English Dictionary
  58. OEM - Original Equipment Manufacurer
  59. OF - Old Fart
  60. OFAY - Offensive term for a white person
  61. OFC - Of course
  62. OFGS - Oh, For God's Sake
  63. OFH - Old Folks' Home
  64. OFL - it means oh what a fricken loonatic
  65. OFN - Old Freaking News
  66. OFOC - Overwhelming Feelings of Concern
  67. OFS - One Finger Salute
  68. OFWGKTA - Odd Future Wolf Gang Kill Them All (rappers)
  69. OGIM - Oh God It's Monday
  70. OGK - Only God Knows
  71. OGKT - Only God Knows That
  72. OGN - Online Gaming Network
  73. OGTDA - One good turn deserves another
  74. OH - Other Half
  75. OHAC - Own House And Car
  76. OHAI - Oh, Hi
  77. OHDH - Old Habits Die Hard
  78. OHEMGEE - Oh my gosh
  79. OHIM - Oh Hell, It's Monday
  80. OHK - Oh,Ok
  81. OHKO - One Hit Knock Out
  82. OHN - Oh Hell, No!
  83. OHOTKOHOTC - One Hand On The Keys, One Hand On The Crotch
  84. OHS - Operator Head Space
  85. OHT - One Handed Typing
  86. OHW - On His Way
  87. OI - Hey
  88. OIB - Oh, I'm back
  89. OIC - Oh, I see
  90. OICN - Oh, I see now
  91. OICU812 - Oh, I See You Ate One Too
  92. OICURMT - Oh, I see you are empty
  93. OIK - Unpleasant, unpopular person
  94. OIS - Oh I see
  95. OITNB - Orange Is The New Black - A popular television ser
  96. OIY - Hey
  97. OJ - Only Joking
  98. OJD - Obsessive Jonas (Brothers) Disorder
  99. OJT - On Job Training
  100. OK - One Kiss
  101. OKBB - OKay, Bye Bye
  102. OKC - Oklahoma City
  103. OKEY DOKEY - OK
  104. OKI - Okey Dokey, OK
  105. OKIES - Okay
  106. OKW/E - OK What-Ever
  107. OL - old lady
  108. OLD BAG - a woman that was once a lovely young women that is
  109. OLDFAG - Long established member of an online community
  110. OLED - Organic Light-Emitting Diode
  111. OLF - One Line Followup
  112. OLL - OnLine Love
  113. OLLG - One Less Lonely Girl
  114. OLN - OnLine Netiquette
  115. OLOY - Only Losers Obey Yolo
  116. OLPC - One Laptop per Child
  117. OLTL - One Life to Live
  118. OM - Old Man
  119. OM NOM - Sound of eating
  120. OMA - Oh My Allah
  121. OMAA - Oh, my aching ass
  122. OMAC - One Man Army Corps
  123. OMB - On My Break
  124. OMD - Oh My Days
  125. OMDB - Over My Dead Body
  126. OMDZ - Oh My Dayz
  127. OMFSM - Oh My Flying Spaghetti Monster
  128. OMFUG - Other Music For Uplifting Gormandizers
  129. OMG - Oh My God
  130. OMGA - Oh My Giddy Aunt
  131. OMGD - Oh My God Dude
  132. OMGNA - Oh My Gosh, Not Again
  133. OMGSH - Oh My Gosh
  134. OMJC - Oh My Jesus Christ
  135. OML - Oh My Legs
  136. OMS - Oh My Science
  137. OMSJ - Oh My Sweet Jesus!
  138. OMT - One More Thing
  139. OMW - On My Way
  140. OMWH - On My Way Home
  141. OMZ - Oh My Zeus
  142. ON - Drunk, high
  143. ON ONE - Under the influence of drugs
  144. ONCO - Or Nearest Cash Offer
  145. ONE - One Love, goodbye
  146. ONE OFF - Happened Once
  147. ONION - Ounce of a drug
  148. ONL - Online
  149. ONM - Oh, Never Mind
  150. ONNA - Oh No, Not Again
  151. ONNTA - Oh No, Not This Again
  152. ONO - Or Near Offer
  153. ONOH - On the Other Hand
  154. ONOZ - Oh No
  155. ONS - One Night Stand
  156. ONTD - Oh No They Didn't
  157. ONTFLMAO - On the floor laughing my ass off
  158. ONUD - Oh No You Didn't
  159. ONYD - Oh no you didn't
  160. OO - OpenOffice
  161. OO2U - Option Open to You
  162. OOA - Out Of Ammo
  163. OOAD - Object Oriented Analysis and Design
  164. OOAK - One Of A Kind
  165. OOBE - Out Of Body Experience
  166. OOC - Out of control
  167. OOE - Out Of Endurance
  168. OOF - a sigh of frustration. Same meaning as the Yiddis
  169. OOFT - Sound made when impressed by something
  170. OOH - On one hand
  171. OOI - Out Of Interest
  172. OOL - Out Of Luck
  173. OOM - Out Of Mana
  174. OOMF - One Of My Friends/Followers
  175. OOML - Out Of My League
  176. OOMM - Out Of My Mind
  177. OOMPR - Out Of My Price Range
  178. OOO - Out Of Office
  179. OOP - Out Of Place
  180. OOPS - Word said after doing something wrong
  181. OOS - Out Of Stock
  182. OOSOM - Out Of Sight Out Of Mind
  183. OOSOOM - Out Of Sight, Out Of Mind
  184. OOT - Out Of Touch
  185. OOTB - Out of the Box
  186. OOTC - Obligatory On Topic Comment
  187. OOTD - Outfit of the day
  188. OOTO - Out Of The Office
  189. OOTQ - Out Of The Question
  190. OOTW - Out Of This World
  191. OOYFM - Out of your fucking mind
  192. OOYL - Out Of Your League
  193. OOYM - Out Of Your Mind
  194. OP - operator
  195. OPA - Greek exclamation
  196. OPB - Other People's Business
  197. OPK - Other People's Kids
  198. OPM - Other People's Money
  199. OPP - A snitch
  200. OPPA - Older brother, male friend
  201. OPPS - A opp is a snitch or person you cant trust there l
  202. OPSEC - Operations Security
  203. OREO - Black on the outside, white on the inside
  204. ORGY - Not Defined
  205. ORITE - Alright, hello
  206. ORKUT - Google's social network
  207. ORLY - Oh Really
  208. ORN - Oh Really Now
  209. ORO - Expression of confusion
  210. ORZ - Frustration, despair
  211. OS - operating system
  212. OSFA - One Size Fits All
  213. OSIF - Oh Shit, I Forgot
  214. OSIM - Oh Shoot It's Monday
  215. OSINTOT - Oh Shit I Never Thought Of That
  216. OSLT - Or Something Like That
  217. OSM - Awesome
  218. OSO - Other Significant Other
  219. OSS - Open Source Software
  220. OSSIM - Awesome
  221. OST - On Second Thought
  222. OT - Off Topic
  223. OT1H - On The One Hand
  224. OT3 - One True Threesome
  225. OTA - over the air
  226. OTAKU - Obsessive fan
  227. OTAOK - Over the air OK
  228. OTASOIC - Owing To A Slight Oversight In Construction
  229. OTAY - Okay
  230. OTB - Off The boat
  231. OTBE - Over Taken By Event
  232. OTC - Over the Counter
  233. OTD - Off the Derech (Way in Hebrew) - someone who is no
  234. OTE - Over the edge
  235. OTF - Its a gang or squads for like field butt it means
  236. OTFL - On the Floor Laughing
  237. OTFLMAO - On the floor laughing my ass off
  238. OTFM - Open The Fucking Manual
  239. OTG - On the ground
  240. OTGH - On The Gripping Hand
  241. OTGL - On the ground laughing
  242. OTH - Off The Hook
  243. OTJ - On The Job
  244. OTK - Over The Knee
  245. OTL - Out to Lunch
  246. OTLTA - One Thing Led To Another
  247. OTMH - Off the top of my head
  248. OTMS - Other Than Mexicans
  249. OTN - Most usages of "OTN" on the Internet these days ar
  250. OTO - One Time Only
  251. OTOH - On The Other Hand
  252. OTOOH - On The Other Other Hand
  253. OTP - If you ask someone what they are doing, and they s
  254. OTR - On the road
  255. OTS - On the scene
  256. OTT - Over The Top
  257. OTTH - On The Third Hand
  258. OTTOMH - Off The Top Of My Head
  259. OTTOMHAROO - Off The Top Of My Head And Rolling Out Of Bounds
  260. OTW - Off To Work
  261. OTY - Over To You
  262. OU - Open University
  263. OUAT - Once Upon A Time
  264. OUCH - Interjection said when experiencing pain
  265. OUGHTA - Ought to
  266. OUNCE - 28 grams of drugs (usually marijuana)
  267. OUO - Official Use Only
  268. OUSU - Oh, You Shut Up
  269. OUTTA - Out Of
  270. OVA - Original Video Animation
  271. OVNO - Or Very Near Offer
  272. OVO - Obviously
  273. OW - Oh Well
  274. OW2TE - Or Words To That Effect
  275. OWFM - Often Works For Me
  276. OWK - Other World Kingdom
  277. OWLING - Crouching and staring like an owl
  278. OWN - Beat, dominate (gaming)
  279. OWNED - Dominated
  280. OWNM - Oh Well, Never Mind
  281. OWOA - One Way Or Another
  282. OWS - Occupy Wall Street
  283. OWT - Anything
  284. OWTTE - Or Words To That Effect
  285. OX - Sharp blade
  286. OXY - OxyContin (or oxycodone), painkiller
  287. OY - Oh Yeah
  288. OYB - On Your Bike
  289. OYE - Listen up
  290. OYG - Oh Your God
  291. OYMSYP - Open your mouth, solve your problem
  292. OYO - On Your Own
  293. OZ - Australia
  294. O_O - Confused
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