antagonistic
an-tag-o-nis-tic
adjective
Showing active opposition or hostility towards someone or something.
"His antagonistic behaviour caused constant arguments."
adjective
Acting in opposition; counteracting or neutralising another's effect.
"These two drugs have antagonistic effects."
Thesaurus
Synonyms: incompatible, antacid, antiphlogistic, antipathetic, hostile, antipathetical, negative, counter, alienating
Antonyms: conciliative, conciliatory, interactive, synergistic