“Verbing” is using a word as a verb that is not really a verb. Like “verb”, there. Guardians of good English usage tend to abhor verbing. Bill Watterson’s Calvin once commented, “Verbing weirds language.” From time to time, though, a verbed noun makes it into the common tongue. “Access” has recently got established as a verb as well as a noun. “Input” gets work as a verb, too.
This probably is no peculiar trend of modern times. There are plenty of words that have been around as both nouns and verbs for a long time. Care, stop, run, walk, talk, record, permit. So maybe it’s not something to fight against all the time.
Some cases are worse than others. Like when there’s a perfectly good verb for what you want to say, but you use a noun as verb instead. Here is an example by Spencer Ackerman where he uses a noun as a verb, seemingly unaware that the noun is in fact derived from a verb that means just what he is trying to use the noun to mean:
I suppose you could rejoinder that we don’t want someone who loses the moral forest for the bureaucratic trees.
That’s what Spencer Ackerman suposes. I would rather suppose you could rejoin that we don’t want someone who loses the moral forest for the bureaucratic trees.
I mean really: that verb is already in the dictionary, and it is fewer characters to type. Go with it!
I would guess that the verb “rejoin” is less familiar than the noun “rejoinder”, so I can understand how this happened, but I think a healthy disdain for verbing might have led Ackerman to ask himself whether there was a real verb he could have used instead of “rejoinder”. If he had asked himself that, maybe he would have found “rejoin” breaking upon his consciousness.