brownout definition
brownout (plural brownouts) 1  A period of low alternating current line voltage, causing a reduction in illumination When demand for electricity exceeds the available supply, a brownout occurs. 2  Temporary dimming of vision, usually with a brown hue and accompanied by loss of peripheral vision or tunnel vision. On rising suddenly from her chair she experienced a brownout and had to sit down again quickly. Temporary closing of a fire station, usually due to budget restrictions.