noun
rodent; gnawing animal
Biological term for animals of the order Rodentia. The gloss 'gnawing animal' is a literal description of the kanji meaning.
ネズミやリスは齧歯動物に分類される。
Mice and squirrels are classified as rodents.
齧歯動物の歯は生涯伸び続ける。
Rodents' teeth continue to grow throughout their lives.
Compound of 齧 (げっ, 'gnaw'), 歯 (し, 'tooth'), and 動物 (どうぶつ, 'animal'). The reading げっ for 齧 is irregular and likely derived from the kanji's on'yomi.