conspicuously and offensively loud; given to vehement outcry; "blatant radios"; "a clamorous uproar"; "strident demands"; "a vociferous mob"
If you describe someone as vociferous, you mean that they speak with great energy and determination, because they want their views to be heard. He was a vociferous opponent of Conservatism = strident + vociferously vo·cif·er·ous·ly He vociferously opposed the state of emergency imposed by the government. expressing your opinions loudly and strongly (vociferari , from vox ( VOICE) + ferre )