- The definition of lessen is to diminish or to cause something to be diminished or reduced.
When you take pain pills and they reduce pain, this is an example of a situation where the pills lessen the pain.
- to make less; decrease
- Archaic to belittle; minimize; disparage
verbless·ened, less·en·ing, less·ens
- To make less; reduce. See Synonyms at decrease.
- Archaic To make little of; belittle.
Origin of lessenMiddle English lessen, lessenen, from lesse, less; see less .
(third-person singular simple present lessens, present participle lessening, simple past and past participle lessened)