Firm with thousand to spend has scope (7)
I believe the answer is:
compass
'scope' is the definition.
(I know that scope can be written as compass)
'firm with thousand to spend' is the wordplay.
'firm' becomes 'co' (a firm is a company).
'with' means one lot of letters go next to another.
'thousand' becomes 'm' (Roman numeral for a thousand).
'to spend' becomes 'pass' ('pass' can be a synonym of 'spend').
'co'+'m'+'pass'='COMPASS'
'has' is the link.
(Other definitions for compass that I've seen before include "Range, extent" , "Direction finding instrument - range" , "Range, area" , "Instrument for determining direction from magnetic needle" , "Box the ---, change fully round" .)