n. 1. attributing to outside causes. [ WordNet 1.5 ]
2. embodying in an outward form. Syn. -- externalisation, exteriorization, exteriorisation. [ WordNet 1.5 ]
v. t. To make external; to manifest by outward form. [ 1913 Webster ]
Thought externalizes itself in language. Soyce. [ 1913 Webster ]