The term 'talk informally' can be represented by two crossword solutions: CHAT (4 letters) and RAP (3 letters). CHAT is a form of communication that involves sending and receiving messages in real time, usually through an online platform. RAP is a musical genre that originated in the United States in the 1970s and is characterized by spoken or chanted rhyming lyrics. Both CHAT and RAP are forms of informal communication that allow people to express themselves in creative ways.