mutability in life or nature (especially successive alternation from one condition to another)
a variation in circumstances or fortune at different times in your life or in the development of something; "the project was subject to the usual vicissitudes of exploratory research"
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