fire blanksfire/shoot blanks [humorous]if a man is firing blanks, there is no sperm (= the cells which combine with the female's egg to start life) in his semen (= the liquid produced in the male sexual organs).
They had a series of fertility tests done and found out that basically Tony was firing blanks. (usually in continuous tenses)
[TahlilGaran] English Idioms Dictionary ▲