uh. the base of this word is "to dominate" this word in this form means something like: "we are going to dominate" these people, or this party. I can't help you with spanish, but since this one word translates to english as five words, it's quite possible there's no single spanish word that means the same thing. This is is what grammar does with words. "Iz-" gives the sense of competition of action, in this case dominance, and "-amo" means that it's "us" who are going to do the dominance. If you give me entire sentence, I can give you more accurate translation. e.g. Ima da izdominiramo ovaj sastanak: We will dominate this meeting

I don't think there is a word 'izdominirati' in Serbian language. You can say dominirati which means to dominate.