Chip in engagement rings, often hollow (6)
I believe the answer is:
donate
'chip in' is the definition.
(thesaurus)
'engagement rings often hollow' is the wordplay.
'engagement' becomes 'date' (synonyms).
'rings' is an insertion indicator (some letters are ringed or contained by others).
'hollow' means to remove the middle letters (the word is hollowed out).
'often' with its centre taken out is 'on'.
'date' placed around 'on' is 'DONATE'.
(Other definitions for donate that I've seen before include "Give - present" , "Contribute (to charity)" , "Give (transplant organ)" , "Give as gift, say blood" , "Make a contribution" .)