1. past tense of externalize; to express or manifest outwardly
Usage: British spelling
2. past tense of externalize; to attribute to factors outside oneself
Usage: psychology; British spelling

Examples

• She externalised her anger by shouting at everyone around her.
• The company externalised its IT services to reduce costs.
• He externalised his problems, blaming others for his failures.
• The therapy helped her understand how she had externalised her guilt.
• The organization externalised many of its non-core functions.
• Students often externalised their academic struggles onto their teachers.