1. The placing of students in any of several courses of study according to ability, achievement, or needs. Also called ability grouping.
2. The position of a magnetic tape as it moves across magnetic heads, as in a VCR.
3. The lateral pressure of a phonograph needle as it tracks in a groove.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.