I’ve had this word on the tip of my tongue, but can’t spit it out.
Say you’re watching a movie set in the 1500s. You see someone with a wristwatch on. WHAT IS THIS CALLED? There’s some word that describes some error in timeline, but I can’t for the life of me remember.
I learned this in like fourth grade. Unfortunately, fourth grade seems to have been replaced in my brain with alcohol and bacon.
I believe the word you’re looking for is “anachronism”, which can refer to anything out of its apparent place in the timestream. Gaslights in the modern US are also an anachronism.