A small vein or veinlet. Recent Dicts. also give veinule ‘a minute vein, a venule’, as a term of Bot. and Geol. (perh. after F. veinule).
1668 Culpepper & Cole Barthol. Anat. ii. vi. 105 There is plenty of blood‥running back from the remotest Veinulets or smallest branches of the Veins. 1846–50 A. Wood Class-bk. Bot. 85 The secondary branches, or those sent off from the veinlets, are the veinulets.