dupe
n.a person who is easily tricked or fooled by someone else. You use this word for someone who is too trusting and gets taken advantage of.
n.a person who is easily deceived or tricked by another. Often carries a pejorative or slightly humorous tone in informal contexts.
“He was a total dupe for the scammer's story.”
“The con artist targeted the elderly man, who was a perfect dupe for his elaborate scheme.”
“While the plot was technically sound, the protagonist's role as a dupe for the villain's plan felt somewhat forced and unconvincing to the audience.”
From French duper, from Middle French duppe, alteration of huppe (“hoopoe”), from Latin, onomatopoeic.
Clipping of duplicate.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.