-sēlə̇s, -sə̇lə̇s sometimes -slə̇s adjective
Etymology: Middle English mercyles, from merci, mercy mercy + -les -less
: having, extending, or showing no mercy : cruel , harsh , pitiless , remorseless
turns a merciless spotlight on the precocious technicians, the spiritual sophomores, and the hairy-chested muscle men of contemporary literature — Gilbert Highet
• mer·ci·less·ly adverb
• mer·ci·less·ness noun -es