Tsk may refer to any of the following:
Tsk is an abbreviation sometimes used for task.
Sounds tsk or tsk-tsk denote disapproval; similar to tut or tut-tut. Below is an example of how this could be used in chat.
User 1: How do you format a drive?User 2: You’re a technician and you don’t know how to format a drive? User 1: Yeah I know. :(User 2: Tsk-tsk!
Chat terms, Pfft