I. boo ‧ me ‧ rang 1 /ˈbuːməræŋ/ BrE AmE noun [countable]
[ Date: 1700-1800 ; Language: Dharuk ]
a curved stick that flies in a circle and comes back to you when you throw it, first used in Australia
II. boomerang 2 BrE AmE verb [intransitive]
if a plan or action boomerangs on someone, it affects them badly instead of affecting the person who it was intended to affect SYN backfire