1.Definition: arousing animosity or hostility
"His antagonistic brusqueness", "Europe was antagonistic to the Unites States"
2.Definition: characterized by antagonism or antipathy
"Slaves antagonistic to their masters"
Related Adjective(s):antipathetic, antipathetical
3.Definition: incapable of harmonious association
4.Definition: indicating opposition or resistance
5.Definition: used especially of drugs or muscles that counteract or neutralize each other's effect