Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† stuppa (less correctly stūpa, stī-pa), ae, f., = στύππη (στύπη), the coarse part of flax, tow, hards, oakum, Plin. 19, 1, 3, § 17; Varr. ap. Gell. 17, 3, 4; Lucr. 6, 880; Caes. B. C. 3, 101; Liv. 21, 8, 10; Verg. A. 5, 682; Pers. 5, 135; cf. Fest. p. 317 Müll.