Anger displayed by some firemen (3)
I believe the answer is:
ire
'anger' is the definition.
(I've seen this before)
'some firemen' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'IRE' is hidden within 'firemen'.
'displayed by' is the link.
(Other definitions for ire that I've seen before include "resentment" , "Anger, annoyance" , "Displeasure" , "Losing head" , "Intense anger" .)