As opposed to warm air flowing up, which is anabatic. Katabatic winds are common around glaciers -- cold air contracts, and so is denser than warmer air, so the air on top of the ice is heavier than air in the valley below. Push it off, and you get wind just from its sinking -- an often cold, and usually very strong wind. Not all mountain winds are katabatic -- chinooks and bergwinds are different processes -- but williwaws, the bura, and the Santa Anas all are. The word was coined in 1918 from Greek katabatikos, a going down, from katabainein, to go down, from kata-, down + bainein, to go.
All flights to and from McMurdo and Scott stations have been canceled due to a katabatic blizzard.