单飞 (pinyin annotated as chán in this entry, but the standard pronunciation is dān fēi) has two distinct senses. Its literal meaning is 'solo flight' — a pilot flying alone or, by extension, a musician going solo after leaving a group. Its figurative, modern slang meaning refers to a married person who goes abroad to work or live without their spouse, often implying the marriage is put on hold. The pronunciation chán is likely a data error (单 only reads chán in the ancient title 单于); learners should use dān fēi in speech.