guru

Borrowed from Hindi गुरु (guru) and Punjabi ਗੁਰੂ (gurū), from Sanskrit गुरु (guru), meaning "venerable, respectable," which originally meant "heavy."

The Sanskrit root's literal sense of physical weight shifted toward figurative weight — someone of gravity and stature worth respecting — before settling into "venerable teacher." A popular but mistaken folk etymology, traced to the Advayataraka Upanishad, reinterprets the syllables as "gu" (darkness) and "ru" (destroyer), giving guru the poetic but unsupported meaning "one who dispels darkness."

It's a doublet of grave, and more distantly cognate with English grieve and brute — all carrying that old thread of heaviness.