Fools, perhaps backtracking under pressure (8)
I believe the answer is:
stressed
'under pressure' is the definition.
(I've seen this in another clue)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for stressed that I've seen before include "exerted pressure" , "Suffering mental strain" , "Tense; highlighted" , "Pressurised, strained" , "Singled out as important" .)