Testicle
There are many slang words for testicles, like balls, nuts, bollocks, nads (short for gonads), crown jewels, testies, marbles, ding dangs, boy toys, boys, nicnaks, plums, and tattay (in Urdu.) In Leviticus 21:20 in the bible (translated into English) they are called stones. Slang words are other names that are used for fun or to be vulgar (rude).