root canal

[valterfaria]

What's the meaning of root canal? (ex. This idea combining dance and gimnastic is about as appealing as a root canal)

[susiedqq]

Having a root canal done by the dentist is painful and costly. No one wants to have it done. It is not a desirable thing to go through. Most people dread it.

The sentence should have read:

This idea combining dance and gimnastic is about as appealing
as having a root canal)