Synonyms and related words :
balanced, bovine, collected, composed, constant, cool, dispassionate, dull, easy, even-tempered, fast, fiducial, firm, firm as Gibraltar, fixed, flinty, immovable, impassive, imperturbable, in equilibrium, inexcitable, inflexible, inirritable, loyal, nonchalant, patient, predictable, relaxed, reliable, secure, set, settled, solid, sot, sound, stable, staunch, steadfast, steady, steely, stoic, stolid, substantial, TRUE, unbending, undeflectable, undisturbable, unflinching, unirritable, unnervous, unpassionate, unruffled, unshakable, unshaken, unswerving, unwavering, unyielding, well-balanced, without nerves