ＮＡＫ

noun

negative acknowledgement; NAK

A control character or signal in data communication indicating that a message was received with errors or cannot be accepted.

• 受信じゅしんがわ側がなっくがＮＡＫを返かえした場ば合あい、送そう信しん側がわはデータを再さい送そうする。

  If the receiving side returns a NAK, the sending side retransmits the data.