To diminish, decrease, or reduce in size, amount, intensity, or degree. lessen implies a gradual or progressive reduction, often suggesting a weakening or mitigation of something.
It can refer to both tangible things like physical size or quantity, and intangible things like pain, impact, or importance.
The act of lessening aims to make something smaller, weaker, or less significant than it initially was.
It often involves active effort to reduce or alleviate a particular condition or state, or it may occur naturally over time through attrition or other external forces.
ABE AB8 EBB
BATE EASE PARE FALL DROP
ABATE LOWER ALLAY
REDUCE MINIFY
ASSUAGE EASEOFF DWINDLE DECLINE SUBSIDE
DIMINISH MITIGATE DECREASE
EXTENUATE ALLEVIATE
DEPRECIATE