Depression

From Old French depression, from Latin depressio.

Full definition of depression

(countable and uncountable; plural depressions)

1879, Richard Jefferies, The Amateur Poacher Chapter 1, It was not far from the house; but the ground sank into a depression there, and the ridge of it behind shut out everything except just the roof of the tallest hayrick.

(psychology) In psychotherapy and psychiatry, a state of mind producing serious, long-term lowering of enjoyment of life or inability to visualize a happy future.
I used to suffer from depression, but now I'm mostly content with my life.
(psychology) In psychotherapy and psychiatry, a period of unhappiness or low morale which lasts longer than several weeks and may include ideation of self-inflicted injury or suicide.
(meteorology) An area of lowered air pressure that generally brings moist weather, sometimes promoting hurricanes and tornadoes.
(economics) A period of major economic contraction.
(economics, US) Four consecutive quarters of negative, real GDP growth. See NBER.
The Great Depression was an event in US history.
(biology, physiology) A lowering, in particular a reduction in a particular biological variable or the function of an organ, in contrast to elevation.