tut-tut
Synonym discussion
Sense: exclamation/1
"Tut-tut" shows mild disapproval, often with an old-fashioned or playful flavor. "Tsk" is a shorter sound and can feel sharper or more impatient, especially when someone makes a small mistake. "Tsk-tsk" is very close to "tut-tut," but modern speakers often use it a little more jokingly. "Shame on you" is much stronger because it openly blames the other person instead of just making a disapproving sound. "Oh dear" is different again: it often shows concern, surprise, or gentle regret rather than telling someone their behavior was wrong. If a child tracks mud across the floor, an older relative might say "Tut-tut." If a friend acts cruelly, "Shame on you" fits better.
Etymology
"Tut-tut" is an imitative English expression based on the small clicking or breathy sound people make to show disapproval. It grew from the shorter form "tut" and became a repeated form because repeating the sound makes the reaction clearer in speech and writing. The verb developed later from that spoken reaction, meaning "to make that sound" or "to speak in that disapproving way."
First known use
1566
1566, in the meaning defined above Verb