verb
-ens; -ened; -ening
to become less hard or firm or to make (something) less hard or firm [no obj]
[+ obj] :to make (something) less dry or rough
[+ obj] :to make (something) less severe, harsh, extreme, etc.
[no obj] :to become less harsh, severe, extreme, etc.
[+ obj] :to make (something) less painful, forceful, or harmful
[+ obj] :to make (something) seem rounder or less sharp
soften up
[phrasal verb]
soften (someone) up or soften up (someone)
to treat (someone) very well or kindly in order to make that person more likely to help you, give you something, etc.
to weaken (an enemy) through military attacks