Monier-Williams: A Sanskrit-English Dictionary (p. 297)
kuṣṭha as, am, m. n. (fr. 1. ku + stha, Pāṇ. 8-3, 97) the plant Costus speciosus or arabicus (used as a remedy for the disease called takman), AV., Kauś. 35, R. ii, 94, 23, Suśr.; the plant Saussurea auriculata; m. (= kakundara) cavity of the loin [Comm.; but perhaps = kūSThikā], VS. xxv, 6; (ā), f. the prominent part of anything, mouth or opening (of a basket) TāṇḍyaBr. xxi PārGṛ. Comm. on, KātyŚr.; = kūSThikā (taken as measure equal to 'one-twelfth') MaitrS. iii, 7, 7; (am) n. leprosy (of which eighteen varieties are enumerated, i.e. seven severe and eleven less so), Suśr., Bhartṛ. i, 89, Kathās.; a sort of poison, L.

Monier-Williams: A Sanskrit-English Dictionary (p. 297)
kuṣṭha as, am m. n. (fr. 1. ku + stha Pāṇ. 8-3, 97) the plant Costus speciosus or arabicus (used as a remedy for the disease called takman), AV.; Kauś. 35; R. ii, 94, 23; Suśr.; the plant Saussurea auriculata; m. (= kakundara) cavity of the loin [Comm.; but perhaps = ku4ṣṭhikā], VS. xxv, 6; (ā), f. the prominent part of anything, mouth or opening (of a basket), TāṇḍyaBr. xxi; PārGṛ.; Comm. on KātyŚr.; = kuṣṭhikā (taken as measure equal to "one-twelfth"), MaitrS. iii, 7, 7; (am), n. leprosy (of which eighteen varieties are enumerated, i.e. seven severe and eleven less so), Suśr. Bhartṛ. i, 89, Kathās.; a sort of poison, L.