If a man is barrel-chested, his chest is round, deep, and sticks out, like the curve of a barrel. It usually suggests a strong, thick upper body — a wrestler, a singer with a big voice, an old sailor — not a thin person, and not simply a fat belly. The word is almost always used of men; you rarely hear it of women. It is descriptive and a little old-fashioned, more at home in stories and portraits than in a doctor's notes. Though actually, it talks about the shape of the chest, not about whether the man is healthy, kind, or overweight. A barrel is the round wooden container; here it is only a picture of shape.