Opinion shifting in spite of vow to ignore son (5,2,4)
I believe the answer is:
point of view
'opinion' is the definition.
(thesaurus)
'shifting in spite of vow to ignore son' is the wordplay.
'shifting' is an anagram indicator.
'to ignore' suggests deleting specific letters.
'son' becomes 's'.
'in'+'spite'+'of'+'vow'='inspiteofvow'
'inspiteofvow' with 's' taken out is 'inpiteofvow'.
'inpiteofvow' is an anagram of 'POINT OF VIEW'.
(Other definitions for point of view that I've seen before include "Way of considering a matter" , "Attitude" , "One's position (regarding something)" , "Way of seeing a matter" , "Opinion" .)