As nouns the difference between nark and nabk
is that
nark is (british|slang) a police spy or informer or
nark can be (
narcotics officer) while
nabk is either of two thorny shrublike trees, of the genus
ziziphus , from north africa and the middle east; (
taxlink) is supposed to be the plant from which christ's crown of thorns was made.
As a verb nark
is (slang) to serve or behave as a spy or informer.