List of acronyms: O

Source: Wikipedia, the free encyclopedia.

This list contains acronyms, initialisms, and pseudo-blends  that begin with the letter O.

For the purposes of this list:

  • acronym = an abbreviation pronounced as if it were a word, e.g., SARS = severe acute respiratory syndrome, pronounced to rhyme with cars
  • initialism = an abbreviation pronounced wholly or partly using the names of its constituent letters, e.g., CD = compact disc, pronounced cee dee
  • pseudo-blend = an abbreviation whose extra or omitted letters mean that it cannot stand as a true acronym, initialism, or portmanteau (a word formed by combining two or more words).
(a) = acronym, e.g.: SARS – (a) severe acute respiratory syndrome
(i) = initialism, e.g.: CD – (i) compact disc
(p) = pseudo-blend, e.g.: UNIFEM – (p) United Nations Development Fund for Women
(s) = symbol (none of the above, representing and pronounced as something else; for example: MHz – megahertz)

Some terms are spoken as either acronym or initialism, e.g., VoIP, pronounced both as voyp and V-O-I-P.

(Main list of acronyms)

  • O – (i) Oberst – Observer – Obstacle – Octal – Officer – Official – Oh – Operational – Operator – Oprah (magazine) – Outstanding – (s) Oxygen

OA

OB

OC

OD

OE

OF

OG

OH

OI

  • OIC – (i) Officer In Charge
  • OIE – (i) World Organisation for Animal Health (originally the Office international des épizooties, French for "International Epizootic Office")
  • OIF – (i) Operation Iraqi Freedom
  • OIOC – (i) Oriental & India Office Collections (in the British Library)

OJ

OK

OL

OM

ON

  1. Historically, as the Irish-language name for the original Irish Republican Army ("Old IRA")
  2. In modern times, as the Irish-language name of the Defence Forces of Ireland
  3. The name of two groups claiming descent from the Old IRA, one a currently inactive splinter group of the Continuity IRA and the other an active splinter group of the Real IRA

OO

OP

OQ

  • OQ - (i) Order Quantity, in inventory management; the quantity of new items to be ordered. Often expressed as a part of OP/OQ (when quantity OP is reached, order OQ new items)

OR

OS

OT

OU

OV

OW

OX

OY

  • Oy – (p) Osakeyhtiö (Finnish, "stock company")
  • Oyj – (p) Julkinen osakeyhtiö (Finnish, "public stock company")

OZ

  • OZ – Ounce