Do you call this "unpicking" or "ripping out?" I was musing over that today while I was... doing it on a project. OK, I'll say it. Ripping out. That's what I've always called it. Maybe it's a midwestern thing. Years ago, my friend from Utah called it "unpicking." Huh? Unpicking? Picking out? No. Unpicking.
Hmmm... makes me wonder if there are any more terms for this unpleasant sewing task in other parts of the country. Well, if you do a google image search on "unpicker" you get 557 results of the standard seam ripper tool. If you do a google image search for "seam ripper" -- how many results do you think there are?
25,900 - "seam ripper" wins