ack 

a human onomatopoeic(sound)word to describe frustration or disgust.

"ACK!!! I have work today, It's going to be a bitch!"

ack by Emily Winters January 5, 2005

ack 

Ack is a word to describe excrement or poo. It can also be used an adjective to describe something with poo-like associations- see Acky.

Where's the toilet? I need to do an ack.
I wouldn't go in there, someone just did an ack.

ack by damon goss October 5, 2011

ACK 

ACK is the call letters for Nantucket Airport, and thus ACK = Nantucket.

What does that "ACK" euro sticker mean? Nantucket.

ACK by Fuzzwuzzy March 10, 2005

ACK 

Used to display displeasure of having to do something you don't want to do.

Ack! Was the sound Bill the Cat made when hacking up a furball, in the cult comic, Bloom County, which Berkley Brethead drew.

"Mike you have to lead the team meeting today."
ACK!

ACK by WTPooh November 30, 2017

ACK 

Something you say like a funny noise in a text, or in real life when you are acting retarded.

*commits die* ACK ACK AKK ACK ACK

ACK by Ihatmylife October 9, 2019

ACK 

The call letters for Nantucket Airport.

duh.

SON: Wow what do all those "ACK" bumper stickers mean?

DAD: Well son they are the call letters for Nantucket airport.

SON: Gee whiz dad! I wish I could be from Nantucket....

DAD: Don't we all son, don't we all- *sigh*

ACK by Chain_Me_Free December 7, 2004

ACK 

the airport call signal for nantucket...like you know, JFK or LAX

Tourist: "excuse me, what does ACK stand for?"
Exasperated Native: "It's the god damn call signal for the airport!"

ACK by ooer May 23, 2005