- Obsolete of, like, or characteristic of the night
- done or occurring every night
- Obsolete at night
- night after night; every night
- Of or occurring during the night; nocturnal: the cat's nightly prowl.
- Happening or done every night: the physician's nightly rounds.
- Every night.
- He checks his email nightly.
From Middle English *nightly, nyÈtly, nihtlich, from Old English nihtlÄ«c, nihtelÄ«c (â€œnocturnal, nightly, of the night, at nightâ€), equivalent to night +â€Ž -ly. Cognate with Scots nichtlie (â€œnightlyâ€), West Frisian nachtlik (â€œnightly, nocturnalâ€), Dutch nachtelijk (â€œnightly, nocturnalâ€), German nÃ¤chtlich (â€œnocturnal, nightlyâ€), Danish natlig (â€œnightlyâ€), Swedish nattlig (â€œnightly, nocturnalâ€).