guru

Etymology

From Hindi गुरु (guru) / Punjabi ਗੁਰੂ (gurū), from Sanskrit गुरु (guru, “venerable, respectable”), originally "heavy" and in this sense cognate to English grieve and, more distantly, brute. Doublet of grave. A traditional, though flawed etymology based on the Advayataraka Upanishad (line 16) describes the syllables gu as “darkness” and ru as “destroyer”, thus ascribing the meaning of “one who destroys/dispels darkness” to the word.

noun

1. In Indian traditions: a spiritual teacher who transmits knowledge to a shishya.
   When the gooroo arrives at the house of a disciple, the whole family prostrate themselves at his feet, and the spiritual guide puts his right foot on the heads of the prostrate family. 1817, William Ward, History, Literature and Religion of the Hindoos, volume II
2. (sometimes humorous) An influential advisor or mentor.
   Many oenophiles rely on the ratings and recommendations of wine guru Robert Parker when selecting the perfect bottle. 18 Oct 2004, “Vintage technology”, in Time
3. (derogatory) A fraudster or conman relying on a projected air of confidence in an obscure field.
   OPCA gurus are modern legal alchemists. They promise gold, but their methods are principally intended to impress the gullible, or those who wish to use this drivel to abuse the court system. Any lack of legal success by the OPCA litigant is, of course, portrayed as a consequence of the customer’s failure to properly understand and apply the guru's special knowledge. 18 September 2012, John D. Rooke, CanLii

verb

1. To act as a guru; to give wise advice