Chat him up. to talk to…. If you chat someone up, usually someone you do not know very well, you talk to them in a friendly way because you are sexually attracted to them. Learn more. Learn the meaning and usage of the idiom 'chat up' with examples and tips on how to use it in conversation. to talk to someone in a way that shows that you are sexually attracted to them: 2. (British English, informal) to talk in a friendly way to somebody you are sexually attracted to, perhaps hoping to start a relationship with them. John was busy chatting up the new girl in his class. . • So I went there and cornered her in the canteen and tried to chat her up for half an hour. She went straight over and tried to chat him up. CHAT SOMEONE UP definition: 1. • While cross-dressing, he never once was found out by men and some attempted to chat him up. To engage someone in light, casual talk, especially in order to gain his or her favor: The salesperson chatted us up for an hour before we finally decided to buy something. See examples of CHAT UP used in a sentence. Chat up definition: to talk flirtatiously to (a person), esp with the intention of seducing him or her. Definition of chat up phrasal verb from the Oxford Advanced Learner's Dictionary. hbigxmvrlxjrcozkeqqwqdbkzwfjlkmbhiklbkinrdulbcuw