also: らちゅう
noun
hairless caterpillar
Refers specifically to a caterpillar that lacks visible hair, often used in contrast to hairy caterpillars (毛虫).
庭の葉っぱに裸虫がついていた。
There was a hairless caterpillar on the leaf in the garden.
He always looks cold, dressed like someone with hardly any clothes.
毛虫 refers to a hairy caterpillar, while 裸虫 specifically means a hairless caterpillar.
Compound of 裸 (hadaka, 'naked') + 虫 (mushi, 'insect'). The reading らちゅう is the on'yomi of the same characters, but its origin is uncertain; it may be an older or specialized reading.