toss a coin
toss a ˈcoin,
ˈtoss for something(especially British English) (also flip a ˈcoin, ˈflip for something usually both American English ) throw a coin in the air in order to decide something: Right, who’s going to wash the dishes tonight? Shall we toss a coin?
Before the coin is thrown, one person chooses either ‘heads’ (= the side of the coin marked with a head) or ‘tails’ (= the other side). If the side chosen lands upwards this person wins the toss and the other person loses.