An
Australian term used to express an unwillingness to
do something or complete a task. Most commonly used in relation to travelling
far distances or going places.
Bloke 1: Me and the boys are gonna go on a road
trip, you wanna come ?
Bloke 2: Nah, sack.
(Alternatively, the word can be used as an adjective.)
Bloke 1: did you wanna come and
rob the 7/11 down the road tonight ?
Bloke 2: Nah, my cars getting serviced, it’s a bit of a sack to
walk there.