Reach firm with million to spend (7)
I believe the answer is:
compass
'reach' is the definition.
(I know that compass is a kind of reach)
'firm with million to spend' is the wordplay.
'firm' becomes 'co' (a firm is a company).
'with' says to put letters next to each other.
'million' 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 "Directional instrument" , "Direction-finding instrument" , "Navigation instrument" , "Orienteering instrument" , "Instrument for determining direction from magnetic needle" .)