Oh, ello!
Bombs are overpowering and destructive. The adjective begins with the letter O.
Outside?
overwhelmingoverwroughtoutstanding
Be optimistic. Recognize that some people are obnoxious.
The Ohio Buckeye tree begins with O. The Oriental Plane tree begins with O.
Melody
orchestrate is an active word that begins with the letter O
A word meaning to leave out which begins with an "o" is omit.
it begins with the letter o. but if you are french, it begins with a letter o.
Bombs are overpowering and destructive. The adjective begins with the letter O.
overdo
Outside?
Offend is a synonym for the word hurt. It begins with the letter O.
One-half is a hyphenated word. It begins with the letter O.
oneodeoreoboeoscillateorangeogreoperateopineobliteratedobdurateobsolete
ophthalmologist
owlish