1 deject, dispirit, oppress, sadden, grieve, cast down, dishearten, discourage, dampen, cast a gloom or pall over, burden, weigh down:
He's very depressed right now because he failed to get a promotion.
2 weaken, dull, debilitate, enervate, sap; depreciate, cheapen, devalue, devaluate; diminish, lower, bring down, reduce:
The news about a new oil field depressed the market today.
3 press (down), push (down) (on), lower:
If the pressure gets too high, just depress this lever.