nocturnally

Nocturnally is an adverb that describes actions or events occurring during the night or related to the night. It is derived from the adjective nocturnal, which means active in the night. The word nocturnal originates from Latin nocturnus 'of the night,' from nox, noctis 'night.' The adverb nocturnally is formed by adding -ly to nocturnal.

In usage, nocturnally is common in scientific writing, particularly in biology and ecology, to denote when an organism is active, for example, "bats forage nocturnally" or "owls hunt nocturnally." It can also appear in speculative or narrative prose to emphasize nighttime settings. In everyday speech, many speakers prefer simpler phrases such as "at night" or "during the night" for clarity, since nocturnally can feel formal or technical. The term is distinct from diurnally, which refers to daytime activity, and from nocturnal (the adjective) which describes the nature of the organism rather than the manner of an action.

Alternative or related terms include nightly, which refers to every night, and cathemeral, describing organisms that are active at irregular intervals during day or night.

See also nocturnal; diurnal; cathemeral.