Wiktionary
n. agent noun of frighten; one who frightens.
Usage examples of "frightener".
Then those bloody big galoots the other week, trying to put the frighteners on us, all over fecking Georgio again.
Terminus, just to put the frighteners on her, Tarantella draped the unconscious rat-baby over the edge of the milk-jug and sauntered off in search of something more appetizing.
Mirandee and the Frightener ate together, and talked long, while Clubfoot listened at a distance.
Millington had come to the conclusion that Welfram was a frightener hired to shake out bad debts: a rent-a-thug in general, not solely Filmer's man.
But the bookie was already out hiring frighteners and the bet had to stand.
Much morp likely that he thought he could put the frighteners quite easily on a paralysed old man and an unworldly woman, and was currently underestimating both the princess’s courage and her husband’s inflexible honour.