KEISTER Meaning of KEISTER in English [ 'ki:stə ](also keester ) ■ noun N. Amer. informal1》 a person's buttocks. 2》 dated a suitcase, bag, or box for carrying possessions or merchandise.OriginC19: of unknown origin. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004