Pubescent Boy (Noun) A male who is arriving at or has reached puberty.

Kiera Knightley, who is filming The Edge of Love -- a film about two women who carrying on a passionate love affair with the poet Dylan Thomas -- recently spoke of her singing talents, after being asked to sing live in the film.

"I went to voice coaching. I was absolutely terrified. I thought my legs were going to buckle and on the first couple of takes I sounded like a pubescent boy! I didn't realise I was going to have to do it live," she told BANG Showbiz. (Source)

Hey, that's funny. Because if it looks like a pubescent boy, and sings like a pubescent boy, well: Maybe ...