What does the cryptic crossword clue "To which pyjamas may be close connection? (7)" mean?

The wordplay uses a charade (building blocks). NIGH (synonym="close") + TIE (synonym="connection") = NIGHTIE The answer is NIGHTIE.

To which pyjamas may be close connection? (7)

Guardian Cryptic #29451 | 4 Down | 2024-08-02 flower