I. ˈtailgate ˌparty BrE AmE ( also tailgate ) noun [countable] American English
a party before an American football game, where people eat and drink near their cars in the ↑ car park of the place where the game is played
II. tail ‧ gate 1 /ˈteɪlɡeɪt/ BrE AmE noun [countable] American English
1 . a door at the back of a truck or car that opens out and down
2 . a tailgate party
III. tailgate 2 BrE AmE verb [intransitive and transitive]
to drive too closely to the vehicle in front of you