The term "Waterfall" was not applied.
but it absolutely was very common to use the process that it implies.
many man-years of gathering requirements, building lists of features, interrogating stakeholders.
people knew they would never get a second chance to get what they wanted, so they would throw every feature in that they could think of.
Then the developers would build it. more man years building. mostly they tested as they went along, but....different features and areas of the app were often build in isolation, so the most you could say was that you had tested what you had built.
the stakeholders were consulted with screenshots, and sometimes the app, but the Big Fear was new features and additional requirements (which would cause massive contractual headaches) so any contact was VERY carefully controlled.
Also it was assumed every project was massively valuable IP, so detailed designs and features were held very close to the chest..again, any contact was VERY carefully controlled.
Eventually, after months or years of effort the various parts of the app would be "merged". omg the cluster fuck that would occur, the compromises, and arguments, the agonizing...
..then more testing..
Once that was completed the brilliant new creation would be seriously unveiled to the users to cheers and relief.
Finally, the contractual battles would begin as the paying company realised they had asked for entirely the wrong thing, and the development company tried desperately to cover their ass and make a profit.
The single biggest problem that Agile fixes isn't the testing, its the disconnect between what the client wanted and what the developers actually deliver.