A call for acknowledgement.
"He hit his head against the wall and let out a loud icq to see if anyone was listening."
In plain English: Icq is an old internet message that tells you someone wants to talk with you right now.
"I checked my old computer to see who was online on ICQ last night."
To send an instant message to (someone) using ICQ.
"I will icq you as soon as I arrive at the airport."
In plain English: To icq means to indicate that you are currently available for messages on your computer.
"He never icqs me anymore since he got married."
A program allowing users to send each other instant messages via the Internet.
"He downloaded an old icq client to reconnect with his friends through instant messages on the internet."
ICQ is a pun based on the phrase "I seek you." The name was chosen because it sounds like those three words when spoken aloud.