| Perilous 1. (a.) Full of, attended with, or involving, peril; dangerous; hazardous; as, a perilous undertaking. 2. (a.) Daring; reckless; dangerous. Thesaurus Entries alarming, bad, chancy, critical, dangerous, dangersome, delicate, desultory, explosive, fraught with danger, hairy, hazardous, infirm, insecure, insubstantial, jeopardous, menacing, parlous, periculous, precarious, provisional, risky, serious, shaky, shifting, shifty, slippery, susceptible, temporary, tentative, threatening, ticklish, tottery, touchy, treacherous, ugly, uncertain, undependable, unfaithworthy, unhealthy, unreliable, unsafe, unsolid, unsound, unstable, unsteadfast, unsteady, unsubstantial, unsure, untrustworthy, vulnerable, wicked |