Meaning of “soften” - Learner’s Dictionary

soften

verb [ I, T ] uk us /ˈsɒfən/
BECOME SOFTER

to become softer or to make something become softer:

Heat the butter until it softens.
BECOME GENTLE

to become more gentle or to make someone or something become more gentle:

Her voice softened.

(Definition of “soften” from the Cambridge Learner’s Dictionary © Cambridge University Press)