gathered together or made less diffuse; "their concentrated efforts"; "his concentrated attention"; "concentrated study"; "a narrow thread of concentrated ore"
of or relating to a solution whose dilution has been reduced
intensely focused; "her concentrated passion held them at bay"
requiring more than usually expected or thought due; especially great patience and effort and skill; "found the job very demanding"; "a baby can be so demanding"
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"