n.
Pronunciation: ' bi-( ˌ )l ō
Function: noun
Etymology: Old Norse bylgja; akin to Old High German balg bag ― more at BELLY
Date: 1552
1 : WAVE especially : a great wave or surge of water
2 : a rolling mass (as of flame or smoke) that resembles a high wave
– bil · lowy \ ' bi-l ə -w ē \ adjective