Shameful - at 144! (5)
I believe the answer is:
gross
I believe this clue is a double definition.
'shameful' is the first definition.
(thesaurus)
'144' is the second definition.
(gross can mean the number 144)
'at' is the link.
(Other definitions for gross that I've seen before include "Hulking" , "Arrant" , "Coarse and crude" , "Flagrant - unpleasant - 144" , "Coarse; repulsive" .)