Possible Clues:

• 'Thug' and 'loot' derive from it
• Language that gave us 'bungalow' and 'guru'
• Language that gave us 'guru' and 'pundit'
• Tongue needs iodine applied to back
• Top-five world language
• India's most prominent language
• Official language of Rajasthan
• Source of “bandanna” and “dungarees”
• Language in Agra
• #4 most spoken language worldwide