It's an interjection meaning either sharp disagreement, an order to shut up, or that the person thinks something is ridiculous.

I don't know "tsss". "Tsk" is an interjection signifying disapproval.

Tsss ?? never heard of it... in what context was it used? Its not a word in the Dictionary. Dont use it would be my advice.

Avril, not a common word at all. Funny, I do think I remember some of my Asian american friends using it ;)

well you have chosen your best answer.. good luck with it.. i have been speaking english for 49 years and i never recall seeing that "word" used in any context... i would not waste my time thinking about it. you would be better off using your energy and learning on mainstream words. Good luck with your learning.