Father looks embarrassed when cut (5)
I believe the answer is:
pared
'cut' is the definition.
(I've seen this in another clue)
'father looks embarrassed' is the wordplay.
I cannot quite see how this works, but
'father' could be 'pa' (pa can mean dad or father) and 'pa' is located in the answer.
'embarrassed' could be 'red' (someone may blush or go red when embarrassed) and 'red' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'when' is the link.
Can you help me to learn more?
(Other definitions for pared that I've seen before include "Trimmed - peeled" , "Of a fruit, peeled" , "Peeled the outer surface" , "Did prune" , "Whittled as with pencil" .)