げそげそげそげそMeanings1adverblooking very thin; gauntonomatopoeic or mimetic wordrare termRare mimetic adverb describing a very thin, gaunt appearance. Often used with する or と. Compare with げっそり, which is more common.See also: げっそり病びょう気きで彼かれはげそげそになった。He became very thin and gaunt due to illness.