com·part·men·tal·ize compartmentalizes compartmentalizing compartmentalized in BRIT, also use compartmentalise To compartmentalize something means to divide it into separate sections. Traditionally men have compartmentalized their lives, never letting their personal lives encroach upon their professional lives. + compartmentalized com·part·men·tal·ized the compartmentalised world of Japanese finance. to divide something into separate areas or groups