Refers to the slow-moving arboreal mammal. Also used figuratively for a lazy person.
I saw a sloth at the zoo.
He doesn't move, like a sloth.
Katakana spelling is also used, especially in zoological contexts.
Rare kanji form; the reading is a gikun/jukujikun.
From 怠け者 (なまけもの), literally 'lazy person', applied to the animal because of its slow movements.