The name Tywin is a boy's name . Tywin.
From the experts:
A seldom-used Game of Thrones name, perhaps because its main originator, Tywin Lannister, is as ruthless as any character in the show. Yet the "ty-" beginning is so ubiquitous and popular that Tywin may have some potential... the fact that it's less well-known than Tyrion probably works in its favor.