An engineer or scientist, especially one engaged in technological or military research.
A person with specialized knowledge or skills, especially one who is socially awkward; (in a weaker sense) an intellectual; a smart person.
An expert in a particular field, especially as called upon to provide comment or opinion in the media; a commentator, a critic.
A native surveyor in British India, trained to carry out clandestine surveillance beyond British borders.
A learned person in India; someone with knowledge of Sanskrit, philosophy, religion and law; a Hindu scholar.