parlous

From Middle English parles, parlous, perlous, [and other forms], a contraction of perilous (“dangerous; dreadful, terrible; morally corrupt, sinful, wicked; inauspicious, unlucky”) (and thus a doublet of perilous), from Old French perilleus, perillos, perillous, perilluse, perilleuse, perilleux (“very dangerous, perilous”) (modern French périlleux), from Latin perīculōsus (“dangerous, hazardous, perilous”), from perīculum (“danger, hazard, peril, risk”) (ultimately from Proto-Indo-European *per- (“to go through, carry forth, try”)) + -ōsus (suffix meaning ‘full of, prone to’ forming adjectives).