The meaning of the Acronym NACK is...

NACK is

• Negative ACKnowledge

More Meanings For NACK:

• Negative ACKnowledge
• Negative ACKnowledge
• Negative ACKnowledge
• Negative ACKnowledge
• Network of Anyone Collecting Keychains

NACK is also in:

• Assembly
• General
• Hobbies
• Networking
• Software