pedant; worthless scholar
A derogatory term for a scholar who is rigidly attached to outdated or impractical ideas, lacking real-world wisdom. Often used in literary or critical contexts.
He is nothing but a pedant, useless for real-world problems.
From Chinese 腐儒 (fǔrú), literally 'rotten scholar'. The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning of a pedantic, useless scholar.