de·pres·sion
dəˈpreSH(ə)n/
noun
1. feelings of severe despondency and dejection.
"self-doubt creeps in and that swiftly turns to depression"
2. a long and severe recession in an economy or market
"the depression in the housing market"
synonyms:
recession, slump, decline, downturn, standstill; stagnation; the Great Depression; stagflation 
"an economic depression"
the financial and industrial slump of 1929 and subsequent years.
singular proper noun: Depression; singular proper noun: Great Depression; noun: the Depression
3. the action of lowering something or pressing something down.
"depression of the plunger delivers two units of insulin"
a sunken place or hollow on a surface.
"the original shallow depressions were slowly converted to creeks"
synonyms:
hollow, indentation, dent, cavity, concavity, dip, pit, hole, sinkhole, trough, crater; More
basin, bowl 
"a depression in the ground"