- parlous: fraught with danger; "dangerous waters"; "a parlous journey on stormy seas"; "a perilous voyage across the Atlantic in a small boat"; "the precarious life of an undersea diver"; "dangerous surgery followed by a touch-and-go recovery"
- (perilously) in a dangerous manner; "he came dangerously close to falling off the ledge"
- (perilousness) hazardousness: the state of being dangerous
- In Arthurian legend, the Siege Perilous (also known as The Perilous Seat) is a vacant seat at the Round Table reserved by Merlin for the knight who would one day be successful in the quest for the Holy Grail. This knight is either Perceval or Sir Galahad, depending on the version of the story. ...
- Dangerous, full of peril