Tanz means a joke, in sarcasm or satire, as a wise-crack; when said not innocently.

This lafz has been used in the classic nazm “Baat Niklegi to duur talak jayegi..”, one of the most memorable songs sung by Jagjit Singh:

Baat Niklegi To Phir…Duur Talak Jayegi
Log Bewajah, Udasi Ka Sabab Poochenge
Yeh Bhi Poochenge, Ki Tum Itni Pareshan Kyun Ho
Ungliyan Uthengi, Sookhe Baalon Ki Taraf
Ek Nazar Dekhenge, Guzreh Huye Saalon Ki Taraf
Choodiyon Pe Bhi, Kayi Tanz Kiye Jayenge
Kaapten Haathon Pe Bhi, fikr-e-kas-e-jaayenge
Log Zaalim Hai, Harek Baat Ka Taana Denge
Baaton Baaton Mein, Mera Zikr Bhi Le Aayenge 
Unki Baaton Ka Zara Sa Bhi Asar Mat Lena…
Warna Chehre Ke Taasur Se Samajh Jayenge
Chahe Kuch Bhi Ho, Sawaalat Na Karna Unse 
Mere Baare Mein Koi Baat Na Karna Unse
Baat Niklegi To Phir…Duur Talak Jayegi

English translation here:
If word gets out then, it will spread far and wide
People will, without reason, question the cause for your sorrow
They will also ask why you look so troubled
Fingers will be raised to your dry, unkempt hair
They will glance shiftily, at the years gone by
Even your bangles will become the subject of sarcasm and jokes (wise-cracks)
(Even the old and the aged, whose hands tremble, will not hesitate to taunt you…)*
People are harsh, they will taunt you on every single thing
Somewhere in the conversation, they’ll mention me too
Don’t pay any attention to their words at all
Or the expressions on your face will give it all away
No matter what happens, don’t question or get into discussion with them
Don’t talk about me with them
If word gets out then, it will spread far and wide