to appear on stage in an amateur capacity / (of a professional) to make a guest appearance / (fig.) to assume a role outside one's usual duties / to substitute for
字串
zì chuàn
(computing) character string (Tw)
反串
fǎn chuàn
(Chinese opera) to play a role outside of one's specialty / (modern) to play a transvestite role / to masquerade as an opponent
成串
chéng chuàn
to be lined up (like a chain of islands, a string of pearls etc) / to form a cluster (like a bunch of grapes) / to come one after the other (like a series of sighs)