I’m not sure if this word usage qualifies as a NotWord, but it certainly qualifies as incorrect. As a university instructor, both on-ground and online, I read a lot of papers. One great mistake I see a lot and which surprises me is the use of since when the author means sense.
Someone will write, for instance, that "his since of timing was off." Clearly, the word here has to be sense. The spell checkers of the world will normally not catch a misused word that is spelled correctly, so even if these students are relying on built-in word processing features, their misused words can easily slip through.
I’m not sure how students make this mistake since the words since and sense sound quite different when pronounced. I can understand typing out one word for another when they sound exactly the same, such as there and they’re, but to use since repeatedly instead of sense tells me something.
And what I think it tells me is that these people didn’t have enough "drill-and-kill" spelling exercises when they were in school, or if they did, they didn’t pay close enough attention to them.
Since this is Monday, that’s my sense of frustration for the week.