Ack 

a bad ack, the opposite of a good crack. Can be used to describe something that is particularly substandard or to denote boredom and/or disinterest

"Do you like that new Starsailor Track?" - "Nah it's Ack"

or

"Alright mate how's it going?" - "Not too good pal, the manager at work says that tar..." - "ACK!"

Ack by Huge Ackman September 16, 2003

ACK 

ACK is used to define Adedayo Charles Kunle, now used as a political term

I acked the election

ACK by ACKCITY November 27, 2018

Ack 

Ack means anonymous cunts kill..
Bahaha.

"ack-"

Ack by ack girl February 19, 2020

Ack 

An expression of a negative emotion which is built up and making one feel ‘poopy’. Used commonly in messaging and social media

‘i’m a whore’
ack

Ack by 1237_ February 20, 2020

Ack 

(v): an insult, usually interchangeable for the word fuck. Can also be synonymous for telling someone/something that they suck

Evan: "Hey guys can you please let me into the studio?"

Everyone: "No, Evan. Ack you."

Ack by _thememeprophet_ April 1, 2020

ack 

*spit*

Worker: acks in coffee
Guy: D;

ack by Fake Repster October 17, 2020

Ack 

Short for “Acknowledged.” Mostly used by military personnel to quickly confirm that they received the sender’s note, email, task, order or request.

“Ack” can also mean “Yes; Ok; Got it; I’m on it; or Confirmed.”

Cpl Smith,

Please follow up with the Chief Engineer to make sure he has everything he requested from our team.

Col T. Taylor

Reply from Cpl S. Smith:

Sir,

Ack.

Cpl S. Smith

Ack by Imakethewordswork April 14, 2021