1. the physiological or psychological response to internal or external stressors. Stress involves changes affecting nearly every system of the body, influencing how people feel and behave. For example, it may be manifested by palpitations, sweating, dry mouth, shortness of breath, fidgeting, accelerated speech, augmentation of negative emotions (if already being experienced), and longer duration of stress fatigue. Severe stress is manifested by the general adaptation syndrome. By causing these mind–body changes, stress contributes directly to psychological and physiological disorder and disease and affects mental and physical health, reducing quality of life. See also chronic stress. [first described in the context of psychology around 1940 by Hungarian-born Canadian endocrinologist Hans Selye (1907–1982)]

2. in linguistics, emphasis placed on a word or syllable in speech, generally by pronouncing it more loudly and deliberately than its neighboring units and slightly prolonging its duration. See also accent.