PUT (OR STICK) ONE'S OAR IN INFORMAL,
Meaning of PUT (OR STICK) ONE'S OAR IN INFORMAL, in English
put ( or stick) one's oar in informal,
chiefly Brit.
give an opinion without being asked.
→ oar
Concise Oxford English vocab.
Сжатый оксфордский словарь английского языка.
2004