- of a sudden
- of age
- of all time
- of course
- of each person
- of import
- of late
- of necessity
- of sound mind
- of the essence
- of unsound mind
- off
- off and on
- off guard
- off her guard
- off his guard
- off ones guard
- off the beaten track
- off the cuff
- off the hook
- off the record
- off year
- off your guard
- off-and-on
- off-axis reflector
- off-base
- off-Broadway
- off-center
- off-centered
- off-color
- off-colour
- off-day
- off-guard
- off-hand
- off-key
- off-licence
- off-limits
- off-line
- off-line equipment
- off-line operation
- off-putting
- off-roader
- off-season
- off-site
- off-speed pitch
- off-street
- off-the-clock
- off-the-cuff
- off-the-peg
- off-the-rack
- off-the-shelf
- off-the-shoulder
- off-the-wall
- off-white
- offal
- offbeat
- Offenbach
- offence
- offenceless
- offend
- offended
- offender
- offending
- offense
- offenseless
- offensive
- offensive activity
- offensively
- offensiveness
- offer
- offer price
- offer up
- offerer
- offering
- offeror
- offertory
- offhand
- offhanded
- offhandedly
- office
- office block
- office boy
- office building
- office furniture
- Office of Inspector General
- Office of Intelligence Support
- Office of Management and Budget
- Office of Naval Intelligence
- Office of the Dead
- office staff
- office-bearer
- officeholder
- officer
- officers mess
- official
- official document
- official emissary
- official immunity
- officialdom
- officialese
- officialise
- officialize
- officially
- officiant
- officiate
- officiating
- officiation
- officious
- officiously
- officiousness
- offing
- offish
- offload
- offprint
- offsaddle
- offset
- offset lithography
- offset printing
- offsetting balance
- offshoot
- offshore
- offshore rig
- offside
- offsides
- offspring
- offstage
- OFlaherty
- Ofo
- oft
- often
- oftener
- oftenness
- oftentimes
- ofttimes