(Biology)a thin-walled hollow organ or cavity in an animal or plant, containing a liquid secretion; a sac, vesicle, or bladder (生)(动、植物)孢囊;囊胞 ■(Medicine)a membranous sac or cavity of abnormal character in the body, containing fluid (医)囊肿 ■a tough protective capsule enclosing the larva of a parasitic worm or the resting stage of an organism (寄生虫幼虫或生物静止期的)包囊
语源
early 18th cent.: from late Latin cystis, from Greek kustis 'bladder'