Turkey boobs are when someone's breasts look like the dangly bit that hangs from a turkeys neck. Yano that manky bit that look like a decended bollock.
Ryan was undressing for the first time in front of Debbie, as she removed her blouse he couldn't help but notice her turkey boobs.
Though historically a term used to describe very large female, or sometimes male, breast, turkey tits have evolved to into a largely undefined term with the only consensus being you know them when you see them. No longer bound by the constraints of a large cup size, turkey tits can actually range from from a B cup all the way up to a 44 triple H. Not to be confused with "Sloppy Hoagie Tits" which are similar yet sloppier, turkey this can be characterized by a dual free wheeling action apart from the "perky" variety, the utmost form of this manifesting as "Sloppy Hoagie Tits" which crosses into a new genus.