Hurting Dad almost completely (7)
I believe the answer is:
painful
'hurting' is the definition.
(similar in meaning)
'dad almost completely' is the wordplay.
'dad' becomes 'pa' (pa can mean someone's father).
'almost' means to remove the last letter (almost the whole word is kept).
'completely' becomes 'in full' (in full means completely or totally).
'infull' with its final letter taken off is 'inful'.
'pa'+'inful'='PAINFUL'
(Other definitions for painful that I've seen before include "Sore" , "Causing trouble or difficulty - it hurts" , "Causing hurt, physical or mental" , "Embarrassing" , "Inflamed" .)