Tense annoyance creates fatigue (4)
I believe the answer is:
tire
'fatigue' is the definition.
(I've seen this before)
'tense annoyance' is the wordplay.
'tense' becomes 't' (abbreviation used in many dictionaries).
'annoyance' becomes 'ire' (I've seen this before).
't'+'ire'='TIRE'
'creates' is the link.
(Other definitions for tire that I've seen before include "Become fatigued" , "Become weary" , "Grow weary of rithe" , "Fatigue" , "Exhaust" .)