Lewis Short
(verb) : immurmŭro (inm-), āre, inmurmuro
* To murmur in, at, or against any thing (poet. and in post-class. prose): ipsa jacet terraeque tremens immurmurat atrae,Ov. M. 6, 558: terrae,id. ib. 11, 187: undis,id. ib. 11, 567: silvis Auster,Verg. G. 4, 261: hastae,Sil. 5, 332: tacita aure (Acestae),Stat. Th. 1, 532: undis,id. ib. 11, 567: illa sibi introrsum et sub lingua immurmurat,Pers. 2, 9: increpor a cunctis totumque immurmurat agmen,Ov. M. 3, 646: ipse publicato nobis, quod immurmurat,whispers,Macr. S. 6, 7: cum saepe immurmurantes audierit ventos,Amm. 12, 16.
Charlton T. Lewis, Charles Short, A Latin Dictionary