extenuate

Short definition from Wiktionary

Verb

1. 1
   To make (something) less dense, or thinner; also, to lower the viscosity of (something).
2. 2
   To make (someone or something) slender or thin; to emaciate, to waste.
3. 3
   To underestimate or understate the importance of (something); to underrate.
4. 4
   To underestimate or understate the importance of (something); to underrate: To diminish or seek to diminish the extent or severity of (a crime, guilt, a mistake, or something else negative) by making apologies or excuses; to palliate.
5. 5
   To beat or draw (a metal object, etc.) out so as to lessen the thickness.
6. 6
   To reduce the quality or quantity of (something); to lessen or weaken the force of (something).
7. 7
   To degrade (someone); to detract from (someone's qualities, reputation, etc.); to depreciate, to disparage.

Adjective

1. 1
   Of a person: emaciated, wasted, weakened; of the body or part of it: atrophied, shrunken, withered.
2. 2
   Of a quality or thing: lessened, weakened.
3. 3
   Reduced to poverty; impoverished.