· opportunity
Outstanding, optimum, optimal
orchestrate is an active word that begins with the letter O
it begins with the letter o. but if you are french, it begins with a letter o.
One-half is a hyphenated word. It begins with the letter O.
onlyonceomenopenomitoverontoovidovum
overdo
Bombs are overpowering and destructive. The adjective begins with the letter O.
off
Outstanding is a nice word. It begins with the letter O.
Outside?
Offensive is a synonym for horrible. It begins with the letter O.
overwhelmingoverwroughtoutstanding
· Organ