Abarim Publications' online Biblical Hebrew Dictionary
The verb צען (sa'an) means to move or travel. This verb appears in several cognate languages and seems to have been a fairly normal word. In the Bible it occurs only in Isaiah 33:20, where it has to do with the moving about of nomads.
Also see the verb יצא (yasa'), meaning to go out, and the possibly related noun צאן (so'n), meaning flock.