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
(chemistry) any theory in which all matter is composed of tiny discrete finite indivisible indestructible particles; "the ancient Greek philosophers Democritus and Epicurus held atomic theories of the universe"
(psychology) a theory that reduces all mental phenomena to simple elements (sensations and feelings) that form complex ideas by association
moral soundness; "he expects to find in us the common honesty and integrity of men of business"; "they admired his scrupulous professional integrity"
an undivided or unbroken completeness or totality with nothing wanting; "the integrity of the nervous system is required for normal development"; "he took measures to insure the territorial unity of Croatia"
inspiring fear; "the formidable prospect of major surgery"; "a tougher and more redoubtable adversary than the heel-clicking, jackbooted fanatic"- G.H.Johnston; "something unnerving and prisonlike about high grey wall"
extremely impressive in strength or excellence; "a formidable opponent"; "the challenge was formidable"; "had a formidable array of compositions to his credit"; "the formidable army of brains at the Prime Minister's disposal"
either of two bean-shaped excretory organs that filter wastes (especially urea) from the blood and excrete them and water in urine; "urine passes out of the kidney through ureters to the bladder"