billow (
http://definr.com/billow)
n : a large sea wave [syn:
surge]
v 1: billow forth; as of smoke or waves [syn:
wallow]
2: move with great difficulty; "The soldiers billowed across
the muddy riverbed"
3: rise and move, as in waves or billows; "The army surged
forward" [syn:
surge,
heave]
4: become inflated; "The sails ballooned" [syn:
balloon,
inflate]