| Lethal 1. (n.) One of the higher alcohols of the paraffine series obtained from spermaceti as a white crystalline solid. It is so called because it occurs in the ethereal salt of lauric acid. 2. (a.) Deadly; mortal; fatal. Thesaurus Entries baleful, baneful, brutal, corroding, corrosive, corrupting, corruptive, counterproductive, damaging, deadly, death-bringing, deathful, deathly, deleterious, destructive, detrimental, disadvantageous, disserviceable, distressing, fatal, feral, harmful, hurtful, injurious, internecine, killing, malefic, malevolent, malign, malignant, mischievous, mortal, noisome, noxious, ominous, pernicious, pestilent, pestilential, poisonous, prejudicial, savage, scatheful, toxic, venenate, veneniferous, venenous, venomous, vicious, virulent |