Borrowed from French protobromure. By surface analysis, proto- + bromură. <span class="searchmatch">protobromură</span> f (plural protobromuri) protobromide...
"before". proto- proto- Romanian terms prefixed with proto- protobiologie <span class="searchmatch">protobromură</span> protocarbură protoclorurat protoclorură protodiacon protodoric protoiereu...