The most common and most likely answer to this crossword clue is the 6 letter word INURED
I
N
U
R
E
D
More clues leading to the result INURED
- Hardened and wronged, Jay’s for retirement
- Used up some older units
- Seasoned judge leaving hurt
- Accustomed to setback in older universities
- Place for students brought up revolutionary, hardened
- Ruined, becoming used to it
- Hardened with hurt lacking justice initially
- Accustomed, coming from college, to turn left?
- Accustomed to be wearing scarlet around university
- Hardened judge leaving hurt
Buddy explains!

The straight part
We know that "Used" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case used = inured.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 INURED mean?
INURED verb- To cause someone to become accustomed to something (usually) unpleasant.
- To take effect, to be operative.
- To commit.