tr.v. reg·u·lat·ed, reg·u·lat·ing, reg·u·lates
1. To control or direct according to rule, principle, or law.
2. To adjust to a particular specification or requirement: regulate temperature.
3. To adjust (a mechanism) for accurate and proper functioning.
4. To put or maintain in order: regulate one's eating habits.
[Middle English, from Late Latin rēgulāre, rēgulāt-, from Latin rēgula, rod, rule; see reg- in the Appendix of Indo-European roots.]
regu·la′tive, regu·la·to′ry (-lə-tôr′ē) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.