bront-
combining form 
or bronto-
Etymology: Greek, from brontē; akin to Greek bremein to roar, bromos loud noise 
 : thunder 
< brontide >
< brontometer >
— often in generic names especially of large animals
< Brontops >
< Brontotherium >
or bronto-
< brontide >
< brontometer >
— often in generic names especially of large animals
< Brontops >
< Brontotherium >