Ring company with millions to spend (7)
I believe the answer is:
compass
'ring' is the definition.
(thesaurus)
'company with millions to spend' is the wordplay.
'company' becomes 'co' (abbreviation).
'with' is a charade indicator (letters next to each other).
'millions' becomes 'm' (abbreviation).
'to spend' becomes 'pass' ('pass' can be a synonym of 'spend').
'co'+'m'+'pass'='COMPASS'
(Other definitions for compass that I've seen before include "Range - direction finder" , "may be boxed" , "Box the ---, change fully round" , "Direction finder; scope" , "Moss cap (anag.)" .)