say it: PER-uh-luhs
perilous is an adjective meaning "fraught with danger". It carries one recorded sense.
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”
Definitions, synonyms and semantic relations for perilous come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.