- one-gene
- one-half
- one-handed
- one-head
- one-holed
- one-horse
- one-horsed
- one-ideaed
- one-layer
- one-legged
- one-line
- one-liner
- one-loop
- one-man
- one-nighter
- one-off
- one-one
- one-pair
- one-parameter
- one-pole
- one-port
- one-row
- one-sided
- one-sidedly
- one-sidedness
- one-stage
- one-star
- one-step
- one-storeyed
- one-storied
- one-track
- one-two
- one-up
- one-upmanship
- one-valued
- one-velocity
- one-way
- onefold
- oneiric
- oneirism
- oneirocritic
- oneirocritical
- oneirocriticism
- oneirodynia
- oneirogenic
- oneirology
- oneiromancy
- onelevel subroutine
- oneman business
- oneness
- oneness modulus
- oner
- onerous
- onerous contract
- onerous contracts
- onerousness
- oneself
- oneway communication
- onfall
- onflow
- ongoings
- onhanger
- onhook
- onion
- onion cutter
- onion dome
- onion ring
- onion twitch
- onion-bed
- onion-couch
- onion-grass
- onion-skin
- onions alloy
- onionskin paper
- oniony
- onkinocele
- onlap
- onlay
- online
- online access
- online ads
- online analysis
- online backup
- online banking
- online buddy
- online charge
- online communication
- online computer
- online computing
- online consumers
- online control
- online database
- online debug
- online debugging
- online diagnostics
- online directory
- online distribution
- online documentation
- online dump
- online edit