Answer: ANTAGONIST

AnswerCrossword Clue
ANTAGONISTIago, notably
ANTAGONISTOpponent.
ANTAGONISTAntonym of ally.
ANTAGONISTAnagram of STAGNATION
ANTAGONISTVillain in a script
antagonistA person who actively opposes or is hostile to someone or something; an adversary
antagonistA muscle whose action counteracts that of another specified muscle
antagonistone that contends with or opposes another
antagonistA substance that interferes with or inhibits the physiological action of another