Abbreviations used in this list:

abbr. abbreviation

ad. adoption

adj. adjective

cont. contraction

der. derived from

n noun

phr. phrase

v verb

OC		Officer Commanding.
O.D.s		Other Denominations (religious denominations other than Church of England).
Odd bod		Strange character.
Old boot		See Camp bike.
Old sweat	phr.	Either a serving soldier with many years service or an ex-serviceman or woman.
On a fizzer		On a charge.
On my/your tod		On my/your own or by myself/yourself.
On the job		Having sex.
On yer bike		Go away; get lost; bugger off; piss off.
OP		Observation Post.
Oppo		Mate
Orderly Joe	phr.	An Orderly Sergeant or duty Sergeant; usually signified by means of a red sash on his duty day.