The most common and most likely answer to this crossword clue is the 8 letter word KNITWEAR
I've seen this crossword clue in The Daily Telegraph
K
N
I
T
W
E
A
R
More clues leading to the result KNITWEAR
- Woollen items knight placed among gear on river
- River attached to name in clothing — Tweed, say?
- Cast-off clothing
- Mixture of ink and water in Jersey and Guernsey, say
- Clothing worn by knight on river — sweaters and things
- Garments found in train wreck, oddly strewn
- Coloured fluid upset, water ruined fleece perhaps?
- Cast off clothing
- I twerk with an eccentric in warm clothing?
- Spilt ink and water that often covers blouses etc
Buddy explains!

The straight part
We know that "apparel" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case apparel = knitwear.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does KNITWEAR mean?
KNITWEAR noun- Knitted garments