What is Chat ?
Chat is (noun) casual friendly talk She likes to drop in for a cup of coffee and a chat. I’d like to have a chat with you about your work. Synonym conversation(verb) to talk in a casual and friendly way They were chatting about their holidays when the bus arrived. to chat someone up to talk to someone with the intention of starting a sexual relationship with them (informal.) He tried to chat up the girl he met in a bar.
source: Easier English, Student Dictionary Upper Intermediate Level