Definitions for "Rotational Latency"
also known as rotational delay. The time taken for a disc to rotate from the current position (on the required track) to the position containing the first required data block.
(computer science) the time it takes for a specific block of data on a data track to rotate around to the read/write head
The amount of delay in obtaining information from a disk due to the rotation of the disk. For a disk rotating at 5200 RPM, the average rotational latency is 5.8 milliseconds. See also Mechanical Latency.