Meaning of blackguard

(noun) someone who is morally reprehensible; "you dirty dog"

(verb) subject to laughter or ridicule; "The satirists ridiculed the plans for a new opera house"; "The students poked fun at the inexperienced teacher"; "His former students roasted the professor at his 60th birthday"

use foul or abusive language towards; "The actress abused the policeman who gave her a parking ticket"; "The angry mother shouted at the teacher"