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
having momentous consequences; of decisive importance; "that fateful meeting of the U.N. when...it declared war on North Korea"- Saturday Rev; "the fatal day of the election finally arrived"
a method of solving simultaneous equations by guessing a solution and then reducing the errors that result by successive approximations until all the errors are less than some specified amount
an occurrence of control or strength weakening; "the relaxation of requirements"; "the loosening of his grip"; "the slackening of the wind"
(physics) the exponential return of a system to equilibrium after a disturbance
(physiology) the gradual lengthening of inactive muscle or muscle fibers