What does the cryptic crossword clue "Unusual feature of night clue (3,5)" mean?

The wordplay uses an anagram. anagram of NIGHT (synonym="NIGHT") + ODD (synonym="ODD") = ODDTHING The answer is ODDTHING.

Unusual feature of night clue (3,5)

Guardian Cryptic #29597 | 6 Down | 2025-01-21 flower