Irritable with no yen for ordeal (4)
I believe the answer is:
test
'ordeal' is the definition.
(thesaurus)
'irritable with no yen' is the wordplay.
'irritable' becomes 'testy' ('testy' can be a synonym of 'irritable').
'with no' is a deletion indicator.
'yen' becomes 'y'.
'testy' with 'y' taken out is 'TEST'.
'for' acts as a link.
(Other definitions for test that I've seen before include "Assess - examination" , "Assay" , "Sample" , "Trial - international game" , "catch trout in it?" .)