(transitive, idiomatic) To talk to (someone) in a friendly, open, or casual manner, sometimes also in a charming or affected manner, usually to curry favor, and sometimes flirtatiously with the intention of establishing a romantic or sexual encounter or relationship with that person.

present participle of chat up

simple past tense and past participle of chat up

Third-person singular simple present indicative form of chat up

(chiefly Britain) Synonym of pick-up line

plural of chat-up line