Army team in vehicle (4)
I believe the answer is:
taxi
'vehicle' is the definition.
(taxi is a kind of vehicle)
'army team' is the wordplay.
'army' becomes 'ta' (abbreviation for Territorial Army).
'team' becomes 'xi' (eleven, a football team).
'ta'+'xi'='TAXI'
'in' is the link.
(Other definitions for taxi that I've seen before include "I hail you!" , "Danny DeVito sitcom" , "Part of fleet" , "Minicab" , "Motor cab" .)