Victory is firm - America is sticky! (7)
I believe the answer is:
viscous
'sticky' is the definition.
('viscous' can be a synonym of 'sticky')
'victory is firm america' is the wordplay.
'victory' becomes 'v'.
'firm' becomes 'co' (a firm is a company).
'america' becomes 'us' (abbreviation for the United States).
'v'+'is'+'co'+'us'='VISCOUS'
'is' acts as a link.
(Other definitions for viscous that I've seen before include "Resistant to flow" , "Treacly" , "Gelatinous" , "Thick and gluey, like heavy oil" , "Thick, sticky (liquid)" .)