adjective: relating to, happening, or active at night
From Latin nocturnalis (of the night), from nox (night). Earliest documented use: 1485
Notes (from Wordsmith)
Pluto’s moon Nix is named after Nyx, the ancient Greek goddess personifying night. In Roman mythology she’s known as Nox. The Latin word for night, nox, also appears in such words as equinox (equal day and night) and noctambulation (sleepwalking).
Usage (from Wordsmith)
“Getting around London late at night used to be expensive or time-consuming. Nocturnal groundlings can now get home more cheaply and reliably.”
After Dark; The Economist (London, UK); Oct 4, 2014.