- Off-center Adj Adv Verb
- Offend Verb
- Offer Noun Verb Adj
- Offer up Verb
- Office Noun Adj Verb
- Officer Noun Adj Verb
- Officialise Verb
- Officialize Verb
- Officiate Verb
- Offlap Noun Verb
- Offline Adj Adv Noun Verb
- Offload Verb Noun
- Offprint Noun Verb
- Offsaddle Verb Noun
- Offset Noun Verb Adj
- Offshore Adj Adv Noun Verb Past Participle
- Ogle Verb Noun
- Oil Noun Verb Adj
- Oink Inter Noun Verb
- OK Adj Adv Inter Noun Verb Pnoun
- Okay Adj Adv Inter Noun Verb
- Olden Adj Verb
- Oleate Noun Verb Adj
- Omen Noun Verb
- Omit Verb
- Onboard Adj Verb
- Onceover Noun Verb
- One-up Verb Adj Noun
- Onlap Noun Verb
- Ooh Inter Verb Noun
- Oomph Noun Inter Verb
- Oophorectomise Verb
- Oops Inter Noun Adj Verb
- Ooze Noun Verb Adj
- Ooze out Verb
- Opacify Verb
- Opalesce Verb
- Opaque Adj Noun Verb
- Open Adj Noun Verb Adv
- Open along Verb
- Open around Verb
- Open back Verb
- Open down Verb
- Open in Verb
- Open off Verb
- Open on Verb
- Open out Verb
- Open over Verb
- Open up Verb
- Operate Verb
- Operate along Verb
- Operate around Verb
- Operate in Verb
- Operate off Verb
- Operate on Verb
- Operate over Verb
- Operate under Verb
- Operationalise Verb
- Operationalize Verb
- Ophthalmoscope Noun Verb