TSK is an onomatopoeic word, which mimics the sound made to express disappointment, disapproval, or annoyance. Some synonyms for TSK include click, tut, cluck, sigh, suck teeth, and hiss. These express the same meaning but differ in sound depending on the language and region. Tut is the sound usually made in British English, while cluck is common in American English. In some cultures, sucking teeth is used to express negative emotions, while in others, hissing is a common way to display disdain. Whatever the sound used, it is universally understood as a nonverbal expression of disapproval.