expression

one at a time: Idiom Meaning and Origin

once or twice: Idiom Meaning and Origin

once in a while: Idiom Meaning and Origin

on board: Idiom Meaning and Origin

oh well: Idiom Meaning and Origin

oh my: Idiom Meaning and Origin

oh dark hundred: Idiom Meaning and Origin

of sorts: Idiom Meaning and Origin

off the radar: Idiom Meaning and Origin

off the hook: Idiom Meaning and Origin

off the back foot: Idiom Meaning and Origin

off one’s trolley: Idiom Meaning and Origin