gu·ru (gr, g-r)
n. pl. gu·rus
1. In Hinduism and Tibetan Buddhism, a personal spiritual teacher.
a. Any of the ten successive spiritual teachers who developed Sikhism between the 16th and 18th centuries.
b. Guru See Guru Granth Sahib.
a. A trusted counselor and adviser; a mentor.
b. A popular or influential leader or advocate, as of a movement or idea: "In a culture that worships slimness, he was the Guru of Lean" (Erica Abeel).
[Hindi guru, from Sanskrit guruḥ, from guru-, heavy; see gwerə-1 in the Appendix of Indo-European roots.]
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.