Lack means to skin a certain bird, according to Spooner (4,3,5)
I believe the answer is:
feel the pinch
'lack means' is the definition.
(lack financial means)
'skin a certain bird according to spooner' is the wordplay.
I cannot quite understand how this works, but
'certain' could be 'the' (definite article - refers to a certain object) and 'the' is found in the answer.
This explanation may well be incorrect...
'to' is the link.
(Other definitions for feel the pinch that I've seen before include "Be in financial difficulties" , "be poor" , "Pretty girl in Italy might" , "Suffer through lack of money" , "Experience financial hardship" .)