- Obliterate Verb
- Obnubilate Verb
- Obrogate Verb
- Obscure Adj Verb
- Observe Verb
- Obsess Verb
- Obsess over Verb
- Obsolete Adj Verb
- Obstruct Verb
- Obtain Verb
- Obtemper Verb
- Obtest Verb
- Obtrude Verb
- Obtund Verb
- Obturate Verb
- Obvert Verb
- Obviate Verb
- Occasion Noun Verb
- Occidentalise Verb
- Occlude Verb
- Occult Adj Noun Verb
- Occupy Verb
- Occur Verb
- Occur along Verb
- Occur around Verb
- Occur on Verb
- Occur over Verb
- Ocellate Adj Verb
- Octroy Noun Verb
- Octuple Adj Noun Verb
- Octuplicate Adj Noun Verb
- Odorize Verb
- Offend Verb
- Offer Noun Verb
- Offer up Verb
- Officialise Verb
- Officialize Verb
- Officiate Verb
- Offlap Noun Verb
- Offload Verb Noun
- Offprint Noun Verb
- Offsaddle Verb Noun
- Offset Noun Verb
- Ogle Verb Noun
- Oil Noun Verb
- Oink Inter Noun Verb
- OK Adj Adv Inter Noun Verb
- Okay Adj Adv Inter Noun Verb
- Omit Verb
- Onboard Adj Verb
- One-up Verb
- Onlap Noun Verb
- Ooh Inter Verb
- Oophorectomise Verb
- Ooze Noun Verb
- Ooze out Verb
- Opacify Verb
- Opalesce Verb
- Open along Verb
- Open around Verb