Lewis & Short

ĭn-ăquōsus a, um, adj., lacking water (post-class.): loca, Cassiod. Hist. Eccl. 1, 1: inaquosus ἄνυδρος, Gloss. Cyril.
As subst.: ĭnăquōsa, ōrum, n. plur., dry places, desert places: serpentes arida et inaquosa sectantur, Tert. Bapt. 1.