ＮＡＫMeanings1nounnegative acknowledgement; NAKcomputing›A control character or signal in data communication indicating that a message was received with errors or cannot be accepted.受じゅ信しん側がわがＮＡＫを返なっくを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.
