- depression
- late 14c. as a term in astronomy, from L. depressionem, noun of action from deprimere "to press down, depress" (see depress). Attested from 1650s in the literal sense; meaning "dejection, depression of spirits" is from 1660s (as a clinical term in psychology, from 1905); meteorological sense is from 1881 (in reference to barometric pressure); meaning "a lowering or reduction in economic activity" was in use by 1826; given a specific application (with capital D-) by 1934 to the one that began worldwide in 1929.