1. one of the small drupes making up an aggregate or multiple fruit like a blackberry • Derivationally related forms: acinar • Hypernyms: drupelet 2. one of the small sacs or saclike dilations in a compound gland • Derivationally related forms: acinar, acinic, acinous • Hypernyms: sac • Part Holonyms: gland, secretory organ, secretor, secreter