lessen

verb (used without object)

1. to become less.

verb (used with object)

2. to make less; reduce.
3. Archaic. to represent as less; depreciate; disparage.

verb

1. to make or become less
2. (tr) to make little of

v.“to become less,” c.1300, from less + -en (1). Related: Lessened; lessening.