per·fid·i·ous adjective \(ˌ)pər-ˈfi-dē-əs\ : not able to be trusted : showing that someone cannot be trusted ei·det·ic adjective \ī-ˈde-tik\ : marked by or involving extraordinarily accurate and vivid recall especially of visual images ric·tus noun \ˈrik-təs\ Definition of RICTUS 1 : the gape of a bird's mouth 2 a : the mouth orifice b : a gaping grin or grimace Origin of RICTUS New Latin, from Latin, open mouth, from ringi to open the mouth; akin to Old Church Slavic rǫgŭ mockery First Known Use: 1827 el·dritch adjective \ˈel-drich\ Definition of ELDRITCH : weird, eerie Origin of ELDRITCH perhaps from Middle English *elfriche fairyland, from Middle English elf + riche kingdom, from Old English rīce — more at rich First Known Use: 1508