1. A truly disgusting (and usually unattractive) individual.
2. A repugnant psychopath that is disliked by most who are acquainted with it. Often oblivious of their own revulsion and of how disliked they truly are.
A combination of the words disgusting and repugnant.
She was the proverbial office pariah - A disgustant and outcast that few would have anything to do with - due in large part to her disagreeable and narcissistic nature.