夜 行 性(やこうせい)

やこうせい

noun

nocturnal; nocturnality

1. nocturnal; being active at night

The characteristic of being primarily active during the night. Used in biology for animals and sometimes humorously for people who stay up late.

フクロウは夜行性(やこうせい)の鳥(とり)だ。

Owls are nocturnal birds.

猫(ねこ)はもともと夜行性(やこうせい)の動物(どうぶつ)だ。

Cats are originally nocturnal animals.

The zoo holds night tours to observe nocturnal animals.

夜行性(やこうせい) is primarily a biological term but is also used colloquially to describe people who are night owls. It modifies nouns with の.

The opposite is 昼行性(ちゅうこうせい) (diurnal — active during the day).

夜行(やこう) (traveling at night) + 性(せい) (nature, characteristic).

Related Words

general

Added 2026.3.11 13:38 · Revised 2026.9.2 13:01

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