Definition of: discoid

(dis′koid) adjective
1. Zool. Having the form of a disk, as certain univalve shells with the whorls coiled in one plane.
2. Pertaining to, like, or forming a disk or disks.
3. Bot. Disk-shaped; rayless, as the tubular central florets of a composite flower, such as the sunflower: also dis·coi′dal.
—noun A disk or disklike object. [<L discoïdes <Gk. diskoeidēs <diskos a discus + eidos form]