(British English, informal)to talk in a friendly way to somebody you are sexually attracted to, perhaps hoping to start a relationship with them(受异性吸引而)亲昵地攀谈,与某人搭讪
She went straight over and tried to chat him up.她径直走了过去试图同他搭讪。
John was in the bar chatting up the barmaid.约翰在酒吧里和酒保聊天。