1.
rodent; rodents (Rodentia)
The biological order Rodentia, comprising mammals such as mice, rats, squirrels, beavers, and porcupines that share continuously growing front incisors used for gnawing. Used both as a technical zoological term and in everyday writing about animals.
鼠は齧歯類だ。
Mice are rodents.
リスや兎も齧歯類に含まれると思われがちだ。
Squirrels and rabbits are often mistakenly thought to be included among rodents.
齧歯類は哺乳類の中で最も種類が多い。
Rodents are the most species-rich group within mammals.
齧歯類の前歯は一生伸び続けるため、常に何かを齧って削らなければならない。
Because rodents' incisors grow continuously throughout their lives, they must constantly gnaw on something to wear them down.
Composed of 齧 (to gnaw), 歯 (tooth), and the suffix 類 (kind; class; -idae). Literally 'the gnawing-tooth class,' the name highlights the defining trait of the order — a single pair of continuously growing incisors in each jaw.
USAGE:
A biological category term, used in science writing, nature documentaries, veterinary contexts, and pet-shop literature. Like other 〜類 group names (哺乳類 mammals, 爬虫類 reptiles), it sounds technical but is fully comprehensible to general readers. Note that rabbits (兎) are NOT rodents — they belong to the order Lagomorpha (兎形目 or ウサギ目) — though many laypeople assume otherwise.
COMMON COLLOCATIONS:
- 齧歯類に属する: to belong to the rodents
- 齧歯類の動物: rodent animals
- 小型の齧歯類: small rodents
- 齧歯目: order Rodentia (formal taxonomic term)
SIMILAR WORDS:
- 哺乳類: mammals — the broader class to which rodents belong
- 鼠: mouse; rat — the most familiar example of a rodent
- 兎形目: order Lagomorpha — the order containing rabbits and hares (often confused with rodents)
- 爬虫類: reptiles — a parallel taxonomic group of similar formality