A son is a male child in relation to his parents. If you're a boy and you have a mother and father, you are their son. Your parents might introduce you by saying, “This is our son, Marcus.”

The word describes a family relationship that lasts your whole life. A man in his fifties is still his mother's son, even though he's an adult. Brothers are the sons of the same parents. A couple with three boys has three sons.

People sometimes use son affectionately when addressing a younger male, even without a family connection. A coach might say “Good effort, son” to encourage a player, or a grandfather might call his grandson's friend “son” as a warm, friendly greeting.

In English, you might see son combined with other words: a grandson is your son's son or your daughter's son, and a stepson is your spouse's son from an earlier relationship.