回溯

to recall / to look back upon

to circle / to go back / to turn around / to answer / to return / to revolve / Hui ethnic group (Chinese Muslims) / time / classifier for acts of a play / section or chapter (of a classic book)

to curve / to return / to revolve

variant of 迴|回[hui2]

to go upstream / to trace the source

variant of 溯[su4]