CIRRUS Meaning of CIRRUS in English n. (pl. cirri) 1. Meteorol. a form of white wispy cloud, esp. at high altitude. 2 Bot. a tendril. 3 Zool. a long slender appendage or filament. Derivatives: cirrose adj. cirrous adj. Etymology: L, curl Oxford English vocab. Оксфордский английский словарь. 2012