Noun
(slang) A cramp-like ache in the testicles and prostate region caused by prolonged sexual arousal; testicles experiencing such an ache.
(slang, figuratively) Unfulfilled sexual desire.
(US, dated, slang) Buboes (in a person of any sex) caused by a sexually transmitted infection; the infection that causes them.
Source: en.wiktionary.orgCould Blue balls be added to the symbol selection? Source: Internet