Adam's apple
From Tardis Wiki, the free Doctor Who reference
File:The Tenth Doctor Regenerates - David Tennant to Matt Smith - Doctor Who - BBC
After regenerating, the Eleventh Doctor feels his Adam's apple, discovering he's male. (TV: The End of Time)
An Adam's apple was a human body part located in the throat.
The Eleventh Doctor, soon after regenerating and not yet aware of his real appearance or gender, thought that he was female due to his hair length, before feeling his Adam's apple to discover that he was male. (TV: The End of Time)
Ace referred to Abner Apple as "Adam's apple" due to his protruding neck. (PROSE: Atom Bomb Blues)