formerly, a castrated man employed as a guard in a harem or as a chamberlain in a palace
Critics are like eunuchs … They see how it should be done … but they can't do it themselves — Brendan Behan
a man or boy deprived of the testes or external genitals
informal a man lacking effectiveness or vitality
[Middle English eunuk via Latinfrom Greek eunouchos bedroom guard, from eunē bed + echein to have, have charge of]