What's the name of this construct - "We went to SuperFunTime, but it really wasn't"?

Where the missing clause is assumed to be a [a super fun time].

Or "Unfortunately, the elastic wasn't". Here it would be wasn't [elastic].

I did try to search, but if this has already been asked it's not easy (for me) to search for.


Ellipsis

https://www.lexico.com/en/definition/ellipsis

noun [plural =] ellipses

  1. The omission from speech or writing of a word or words that are superfluous or able to be understood from contextual clues. ‘it is very rare for an ellipsis to occur without a linguistic antecedent’