Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
bŏo (with the digamma bŏvo, Enn.; v. infra), āre or ĕre, v. n. [from the root bo, kindr. with Sanscr. gu and the Gr. βοάω; cf. Varr. L. L. 7, § 104 Müll.; Non. p. 79, 4; acc. to Paul. ex Fest. p. 30 Müll. directly from the Gr.], to cry aloud, roar (mostly ante- and post-class., and in the poets).
bŏvo, v. boo.