1. The placing of students in any of several courses of study according to ability, achievement, or needs. Also called ability grouping.
2. A control mechanism that adjusts that lateral pressure of a phonograph needle as it tracks in a groove.
3. A control mechanism that adjusts the position of a magnetic tape as it moves across magnetic heads, as in a VCR.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.