Army team's vehicle (4)
I believe the answer is:
taxi
'vehicle' is the definition.
(taxi is a kind of vehicle)
'army team's' is the wordplay.
'army' becomes 'TA' (abbreviation for Territorial Army).
'team' becomes 'xi' (a football team, from Roman numerals for 11).
'ta'+'xi'='TAXI'
(Other definitions for taxi that I've seen before include "Hired vehicle" , "Vehicle with a meter" , "Minicab" , "Prepare to fly" , "Move along a runway" .)