Ack is a antonym of nack.
As a verb nack
is to acknowledge negatively; to send a NAK signal to.
As a noun ACK is
an acknowledgement either of a packet or a message received from a network.
As an interjection ack is
acknowledged.
nack
English
Verb
(
en verb)
(computing) To acknowledge negatively; to send a NAK signal to.
ack
Alternative forms
* ack
Noun
(
en noun)
(internet) An acknowledgement either of a packet or a message received from a network.
Antonyms
* NAK