A chap is a friendly guy or a regular fellow.
The word "chap" is often used informally and colloquially to refer to a man who's not necessarily a close friend, but someone you know casually. For example, if you meet a guy on vacation and have a nice conversation with him, he might become your "chap for the day." You can also use it to describe an acquaintance or a colleague, like saying "I met my chap at work yesterday" to indicate that they're not exactly close friends, but you've gotten to know them.
(obsolete outside Britain and Australia) A man, a fellow.
Example: Who’s that chap over there?
