What is the meaning of Wallen?

plural of wal

to move violently, to seethe [auxiliary haben]

to roil [auxiliary haben]

to undulate, to flutter, to palpitate [auxiliary haben]

to move (somewhere) while undulating, to billow, to flow [auxiliary sein]

to walk solemnly, to walk with a measured pace

to go on a pilgrimage

to well up

to boil

Source: wiktionary.org