Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. ē-rūgo, āre, v. a., to clear from wrinkles, to smooth, Plin. 13, 12, 26, § 82; 21, 19, 74, § 127; 28, 12, 50, § 183.
‡ 2. ē-rūgo, ĕre, semel factum significat, quod eructare saepius, Paul. ex Fest. p. 83, 1 Müll.
Hence, * ēructus, a, um, P. a., belched out; transf., impure, bad: vinum (with fetidum), Gell. 11, 7, 3.