The most common and most likely answer to this crossword clue is the 3 letter word AWN
A
W
N
More clues leading to the result AWN
- A positive outcome, losing one's beard
- A couple of points making us bristle!
- At first, articles will nestle in beard
- Bristle, displaying anger with new leaders
- Bristles angrily when nagged, first of all
- Beard beginning, shaved at the top
- Outgrowth on cereal grass not long
- Lower head of pale bristly growth
- Grass cut first then hair
- Stiff bristle found in a field of mowed grass needs no introduction
Buddy explains!

The straight part
We know that "Stiff bristle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case stiff bristle = awn.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 AWN mean?
AWN noun- The bristle or beard of barley, oats, grasses, etc., or any similar bristlelike appendage; arista.