The phrase "most intermutual" refers to something that is highly reciprocal or mutual, indicating a strong exchange or sharing relationship between two or more parties. Its antonyms, on the other hand, would suggest the opposite - a lack of reciprocity or mutualism. These antonyms could include words like selfish, non-cooperative, non-reciprocal, unilateral, disconnected, or self-centered. Using these words to describe a situation or relationship would indicate that there is little to no movement or sharing going on between the parties involved, and that one party may be taking more than giving in the relationship.