defeminise BrE
defeminize AmE

A male teacher would both encourage kids to emulate an intelligent adult, and "defeminize the early learning atmosphere."

Many females complained that the male-dominated military sought to defeminize servicewomen while denying them equal treatment.

Early androgen treatment has been shown to masculinize and defeminize such vocalizations by shifting their features towards male-typical patterns and away from female-typical patterns.