Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

as-sŏno (ads-, Jahn; ass-, Merk.), āre, v. n., to sound to, respond to (rare): plangentibus assonat Echo, Ov. M. 3, 507: reparabilis adsonat Echo, Pers. 1, 102.
With acc. of similar signif.: ut canorae aviculae concentus suaves adsonarent, struck up, App. M. 11, p. 260.