harshly uninviting or formidable in manner or appearance; "a dour, self-sacrificing life"; "a forbidding scowl"; "a grim man loving duty more than humanity"; "undoubtedly the grimmest part of him was his iron claw"- J.M.Barrie
impervious to pleas, persuasion, requests, reason; "he is adamant in his refusal to change his mind"; "Cynthia was inexorable; she would have none of him"- W.Churchill; "an intransigent conservative opposed to every liberal tendency"
shut out from view or get in the way so as to hide from sight; "The thick curtain blocked the action on the stage"; "The trees obstruct my view of the mountains"
hinder or prevent the progress or accomplishment of; "His brother blocked him at every turn"