To become a Buddhist "monk" or "nun" is called chūjiā 出家. What is it called to take Catholic orders, other than dāng shénfù 當神父, etc.?
Edit (after reading some comments): A former Dominican novice told me that 出家 is sometimes used in the case of taking monastic orders. I'd be especially interested to hear from other people who have first-hand experience with this calling in a Chinese-language context.