Organization is a group word. It means a body of people grouped together with some purpose.
An ORDER of people
A word meaning to leave out which begins with an "o" is omit.
orchestrate is an active word that begins with the letter O
Orchestra
Bombs are overpowering and destructive. The adjective begins with the letter O.
it begins with the letter o. but if you are french, it begins with a 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
obnoxious?
off