n A throw, a lob, of a ball etc., with an initial upward direction, particularly with a lack of care.
n (cricket|football) The toss of a coin before a cricket match in order to decide who bats first, or before a football match in order to decide the direction of play.
n (British|slang) A jot, in the phrase 'give a toss'.
v To throw with an initial upward direction.
v To flip a coin, to decide a point of contention.