- organic heart disease
- on the latch
- ordnance stores
- ordnance
- one flame kindles another
- one's boat to sink
- on the job
- optical maser
- on time
- operative
- operations research
- operative cholangiography
- one who lives in good
- offerings pledged to a deity on fulfilment of some desire
- opisthorchiasis
- opition
- out of one's depth
- operating capability
- one of the two major sects of the muslims
- one of the two major sub_divisions of mohammedans (the other being
- one who gives love and affection
- of or pertaining to a peasant
- on guard
- or mixer
- or of the shape of
- or whenever
- one more (than)
- on an ad hoc basis
- on an even keel
- on person
- on the altar of
- on account
- one who reflects and deliberates on shastras
- one who relishes
- of the highest order
- out of the hat
- one quickly after the other
- one pip (in a dice)
- out of time
- onion thrips
- onion louse
- on the tip of the tongue
- one who dons clothes made of
- one who does not talk out secrets
- once upon a time
- one who is not sincere in one's dealings
- on the damp side
- outer table
- one of the seven nether worlds
- one of the four vedas