ex·ter·nal·ize / ikˈstərnəˌlīz/ • v. [tr.] (usu.be externalized) give external existence or form to: elements of the internal construction were externalized onto the façade. ∎ express (a thought or feeling) in words or actions: an urgent need to externalize the experience. ∎ Psychol. project (a mental image or process) onto a figure outside oneself: such neuroses are externalized as interpersonal conflicts. DERIVATIVES: ex·ter·nal·i·za·tion / ikˌstərnəliˈzāshən/ n.