Lewis & Short

sŭb-obscūrus, a, um, adj., somewhat obscure; trop., of language: breves et ob eam ipsam causam interdum subobscuri, Cic. Brut. 7, 29: ingressio, id. Or. 3, 11: cicatrix, Vulg. Lev. 13, 21.
Adv.: sŭbob-scūrē, somewhat obscurely: dixit, Gell. 10, 1, 7: explicat, id. 3, 14, 6.