(not North America, uncountable) association football: a game in which two teams each contend to get a round ball into the other team's goal primarily by kicking the ball.
Each team scored three goals when they played football.
(US, uncountable) American football: a game in which two teams attempt to get an ovoid ball to the end of each other's territory.
Each team scored two touchdowns when they played football.
(Canadian, uncountable) Canadian football: a game played on a wide field in which two teams attempt to get an ovoid ball to the end of each other's territory.
They played Football in the snow.
(Australian, Victoria, South Australia, Western Australia, Tasmania, Northern Territory, uncountable) Australian rules football.
(Australian, New South Wales, Queensland, uncountable) rugby league.
(countable) The ball used in any game called "football".
The player kicked the football.
(uncountable) Practise of these particular games, or techniques used in them.
(metaphorical, countable) An item of discussion, particularly in a back-and-forth manner
That budget item became a political football.
(Irish, uncountable) A field game played with similar rules to hurling, but using hands and feet rather than a stick, and a ball, similar to, yet smaller than a soccer ball.
(slang, countable) The nickname of the leather briefcase containing classified nuclear war plans, which is always near the US President.