guru-n; 2 Senses

Sense Number 1: spiritual leader or guide

Commentary: GURU[+entity][+person][+guide][+spiritual]

Mary studied with a guru in India for two years.
A religious guru in Oregon was indicted for tax evasion.
Our guru encouraged us to meditate every day and become vegetarians.

WordNet 3.0 Sense Numbers: 1

Sense Number 2: an expert in a knowledge domain

Commentary: GURU[+entity][+person][+expert][+domain][+knowledge]

Several gurus of game development will be at the conference.
They've called in some marketing gurus to help with the product launch.
I am no Unix guru, but I do know a few useful commands.

WordNet 3.0 Sense Numbers: 3