The most common and most likely answer to this crossword clue is the 7 letter word TORMENT
I've seen this crossword clue in The Times
T
O
R
M
E
N
T
More clues leading to the result TORMENT
- Troops engaged in uphill jog suffering
- Pester chaps involved in civil wrong
- Wrong to keep people in terrible pain
- Some angst or mental agony
- Chaps on rocky peak finally broadcast anguish
- In plague, wrong to hold hands
- Run back around troops causing distress
- Curse as no room squeezing into big top?
- Anguish of Cyclops name being implicated in wrongdoing
- Contrary communist grasping chaps annoy
Buddy explains!

The straight part
We know that "suffering" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case suffering = torment.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 TORMENT mean?
TORMENT noun- A catapult or other kind of war-engine.
- Torture, originally as inflicted by an instrument of torture.
- Any extreme pain, anguish or misery, either physical or mental.
- To cause severe suffering to (stronger than to vex but weaker than to torture.)