Lewis Short
con-frĕmo, ŭi, 3
* V. n., to sound aloud, resound, to murmur loudly, etc. (poet. and rare): confremuere omnes,Ov. M. 1, 199; Stat. S. 1, 6, 72: confremit et caelum et ... circus,Sil. 16, 398: collis,Stat. S. 1, 4, 14.
Charlton T. Lewis, Charles Short, A Latin Dictionary