1.Definition: becoming progressively lower
"The down trend in the real estate market"
2.Definition: being or moving lower in position or less in some value
"Lay face down", "The moon is down", "Our team is down by a run", "Down by a pawn", "The stock market is down today"
3.Definition: being put out by a strikeout
"Two down in the bottom of the ninth"
4.Definition: extending or moving from a higher to a lower place
"The down staircase", "The downward course of the stream"
5.Definition: filled with melancholy and despondency
"Downcast after his defeat", "Feeling discouraged and downhearted"
6.Definition: lower than previously
"Prices are down"
7.Definition: not functioning (temporarily or permanently)
"We can't work because the computer is down"
"The shades were down"
9.Definition: understood perfectly
"Had his algebra problems down"