Extenuate

rozcieńczać

(to make (something) less dense, or thinner; to lower the viscosity of (something))

rozcieńczyć

(to make (something) less dense, or thinner; to lower the viscosity of (something))

wychudzać

(to make (someone or something) slender or thin — see also emaciate)

wychudzić

(to make (someone or something) slender or thin — see also emaciate)