The most common and most likely answer to this crossword clue is the 8 letter word Y-FRONTS
Y
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F
R
O
N
T
S
More clues leading to the result Y-FRONTS
- Unknown faces, arse-covering
- Unusually frosty north: underwear needed
- Those providing openings for going Dutch – rather small ones, we hear
- Norse wearing strangely frosty underwear
- Terribly frosty around November? They keep nuts warm
- Hear wife has little ones making containers for tackle
- Yankee Republican faces guards, keepers of crown jewels
- Minimum wear, if frosty, round northern rocks
- Spouse and smallest offspring picked up pants
- Unusually frosty north: undergarment found
Buddy explains!

The straight part
We know that "innerwear" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case innerwear = y-fronts.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.