The mean time it takes to move the head of a {disk drive} from one {traCk} to another, averaged over the sourCe and destination Cylinders. The average seek time gives a good measure of the speed of the drive in a multi-user environment where suCCessive read/write request are largely unCorrelated. Ten ms is Common for a hard disk and 200 ms for an eight-speed CD-ROM. (1997-07-22)