1. past tense and past participle of imperialise; to bring under imperial control or to extend imperial rule over a territory or people
Usage: chiefly British spelling (American: imperialized); historical context
2. to give an imperial character or status to something; to make imperial in nature or appearance
Usage: less common usage

Examples

• The European powers imperialised much of Africa during the 19th century.
• Britain imperialised India over the course of two centuries.
• The regime imperialised the surrounding regions through military conquest.
• Colonial administrators imperialised local governance structures.
• The nation imperialised its territories to expand its global influence.