When was "Guru" - sanskrit term meaning teacher - popularized?

I was interested to know about term Guru, when it was popularized really in Western countries ? At first I was trying to do a google books search of a word which showed that popularity of phrase sharply increased in 1955. So first question would be what affected such increase in popularity of "Guru" in google books at that time ? My first guess is that because of movie "MR. & MRS. ’55 (1955)" where director and one of cast crew is Guru Dutt. If it is so then event is not related to "Guru" term as a teacher at all. And second question would be - When really Guru synonym of teacher was really popularized in Western culture / countries ? Was "Guru" term popularized because of guru movement and interaction with hippies at 1960s-1970s at Western Europe and USA ? Or some other event induced peak in term's popularity ?

Solution 1:

guru a noun Etymonline 1940:

Generalized sense of "mentor" is from 1940 (in H.G. Wells); sense of "expert in something" first recorded c. 1966 in Canadian English in reference to Marshall McLuhan.

From this citation, guru pre-dates the hippies. Your reference to the movie seems unlikely as just an actor named Guru (1st name) was in it.

The OED says the following and dates early usage to ~ 1600:

• A Hindu spiritual teacher or head of a religious sect. Also in gen. or trivial use: an influential teacher; a mentor; a pundit.

1613 S. Purchas Pilgrimage 500 They have others which they call
Gurupi, learned Priests.

Other synonyms and their dates:

• catechizer (c1449)

• mystagogue (c1540)

• oracle (1548)

• catechist (1564)

• guru (1613)

• director (1671)

• swami (1901)