I throw the ball, written in Greek, you can use the same words, but with different verb voices.
I throw the ball - in active voice, I'm throwing a ball away from myself.
I throw the ball - in passive voice, I'm thrown the ball from someone else.
I throw the ball - in the middle or reflexive voice, I throw the ball to myself.
So you can write the same words, but the different forms show who's doing the action, and towards whom.
So in this case, anti - against; tasso, to position or appoint, I think
@Hidden In Him ; by the word we know this is to position against, by the voice we know that it's the person positioning themself against.