As verbs the difference between dack and nack
is that dack is (australia|informal) to pull down someone's trousers as a practical joke while nack is (computing) to acknowledge negatively; to send a nak signal to.
dack
English
Verb
(
en verb)
(Australia, informal) To pull down someone's trousers as a practical joke.
nack
English
Verb
(
en verb)
(computing) To acknowledge negatively; to send a NAK signal to.