Inaccuracy come where you mad a bad move. Not that bad but is something you want to avoid. It leads to a very bad move. However you can fix it. If you made an inaccuracy move, try to fix and adjust that move. Try to make the game better. And inaccuracies do exsist.
what is an "inaccuracy"?

Inaccuracy come where you mad a bad move. Not that bad but is something you want to avoid. It leads to a very bad move. However you can fix it. If you made an inaccuracy move, try to fix and adjust that move. Try to make the game better. And inaccuracies do exsist.
This doesn't make any sense. And no, this has nothing to do with how chess.com uses the term.

Inaccuracies do not exist.
Either a move worsens the game state won / drawn / lost, or it does not.
If it worsens the game state, then it is a mistake (?) instead of an inaccuracy.
If it does not worsen the game state, then it is not inaccurate.
Every reader should be warned that this is tygxc's own definition which no one else uses and no one agrees with. Chess.com uses these terms differently.
Not to mention that the OP probably got his answer in the past 6 years.
Everyone should be warned that this is magipi's own peculiar way of answering constructive forum posts by pointing out unhelpful things.

Could it also be a "dubious" move, whose effects are not entirely clear?
I think the name for that is "interesting" move.
Perhaps the confusion arises because one is an exclamation mark followed by a question mark, the other reverses them.

Could it also be a "dubious" move, whose effects are not entirely clear?
This has again absolutely nothing to do with how chess.com uses the term. In chess.com, there is a simple arithmetic: the engine evaluation of the top move minus the engine evaluation of the current move. If it's very small, then it's called a "good move". If it's somewhat larger, "inaccuracy", then "mistake", then "blunder". It is probably also somewhat adjusted by the rating of the players.
All this is a very mechanical thing and it has nothing to do with how a human would use these term or with other factors. It's also extremely unhelpful for the players involved.
I have certainly won games in which I was evaluated as committing one or more blunders (maybe the opponent did worse). More often, alleged mistakes have actually set up a win. At least at lower levels they do not necessarily have the negative effects that might be expected.