Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prūna [root in Gr. πῦρ, fire], ae, f., a burning coal, live coal (cf. carbo): medium per ignem multā premimus vestigia prunā, Verg. A. 11, 788 Serv.; 5, 103: latum clavum prunaeque batillum, Hor. S. 1, 5, 36; Plin. 20, 6, 23, § 54; 29, 3, 11, § 45 al.
prūnum, i, n. [prunus], a plum: cerea, Verg. E. 2, 53: cereola, Col. 10, 404; 12, 10, 2; Plin. 15, 13, 13, § 44: spini jam pruna ferentes, Verg. G. 4, 145; Ov. M. 13, 817; Mart. 13, 29, 1.
† prūnus, i, f., = προύνη, a plum-tree, Verg. G. 2, 34; Plin. 13, 10, 19, § 65; Pall. Nov. 7, 14; id. Feb. 25, 32.
Esp.: prunus silvestris, the blackthorn, sloe-tree, Col. 2, 2, 20; Plin. 18, 6, 7, § 34.