demandant
noun
de·man·dant di-ˈman-dənt 
1
archaic : the plaintiff in a real action
2
archaic : one who makes a demand or claim
Word History
Etymology
Middle English demaundant, borrowed from Anglo-French, "questioner, claimant, plaintiff," noun derivative from present participle of demander, demaunder "to ask a question, claim as due" — more at demand entry 2
First Known Use
15th century, in the meaning defined at sense 1