deuteragonist
noun
deu·ter·ag·o·nist ˌdü-tə-ˈra-gə-nist 
also ˌdyü-
1
: the actor taking the part of second importance in a classical Greek drama
2
: a person who serves as a foil to another
Example Sentences
Recent Examples on the Web In fact, nearly every single Resident Evil entry places a woman as either a protagonist, a deuteragonist, a crafty villain, or both in some instances. 
Brittany Vincent, Wired, 7 May 2021 The three-minute video features the new deuteragonist, Spartan Locke, who’s going to be filling in for the Master Chief as the resident gun-with-a-camera-attached for parts of the game, which releases October 27. Jake Muncy, WIRED, 1 Sep. 2015
Brittany Vincent, Wired, 7 May 2021 The three-minute video features the new deuteragonist, Spartan Locke, who’s going to be filling in for the Master Chief as the resident gun-with-a-camera-attached for parts of the game, which releases October 27. Jake Muncy, WIRED, 1 Sep. 2015 Word History
Etymology
Greek deuteragōnistēs, from deuter- + agōnistēs combatant, actor — more at protagonist
First Known Use
1855, in the meaning defined at sense 1