An oar that is worked with great effort. / (chiefly US, figuratively, by extension) The part of a task that requires the greatest effort to achieve.

plural of oar-hole

(idiomatic, UK) To meddle; to stick one's nose into (something)

An interest in someone else's affairs, possibly through meddling.

Synonym of stick one's oar in (“to interfere”)

Synonym of stick one's oar in (“to interfere”)

(slang, of a person) To be crazy.