The most common and most likely answer to this crossword clue is the 5 letter word SARIS
S
A
R
I
S
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The straight part
We know that "attire" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case attire = saris.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 SARIS mean?
SARIS noun- The traditional dress of women in the Indian Subcontinent; an outer garment consisting of a single length of cotton or silk, most often with one end wrapped around the waist to form a skirt, the other draped over the shoulder or head.