tonitrus ūs, m plur nom. and acc. tonitrūs m or tonitrua, n tono, thunder: tonitrum secuti nimbi, O.: caelum tonitru contremit, C. poet.: tonitruque tremescunt Ardua terrarum, V.: tonitrūs sinistri, O.: inter fulmina et tonitrua: tempestas cum magno fragore tonitribusque, L.: movere tonitrūs, O.