I was looking up on the web but the best antonym of fad that I could find was 'standard'. It is close but not quite accurate in my opinion. Any other suggestions? For instance, what would be the most appropriate last word in the following sentence:
Are fidget spinners just a fad or _____.
Best Answer
As the other answers suggest there are several ways of saying what you want to say, but in the context of the sentence that you provided, I would suggest "here to stay."
"Are fidget spinners just a fad, or here to stay."
Reference: Cambridge Dictionary