What does the cryptic crossword clue "Neckwear could be junk, mostly (3)" mean?

The definition is "Neckwear". The wordplay uses a deletion. BOA (deletion) = BOA; definition: "Neckwear" The answer is BOA.

Neckwear could be junk, mostly (3)

Guardian Cryptic #28945 | 19 Across | 2022-12-20 flower