billow

Etymology

From Middle English *bilowe, *bilewe, *bilwe, *bilȝe, borrowed from Old Norse bylgja, from Proto-Germanic *bulgijō. Cognates include Danish bølge, Norwegian Bokmål bølge, Norwegian Nynorsk bylgje, Middle High German bulga and Low German bulge.

noun

1. A large wave, swell, surge, or undulating mass of something, such as water, smoke, fabric or sound
   […] Whom the winds waft where'er the billows roll, / From the world's girdle to the frozen pole; 1782, William Cowper, “Expostulation”, in Poems by William Cowper, of the Inner Temple, Esq.
   The snow fell hissing in the brine, / And the billows frothed like yeast. 1842, Henry Wadsworth Longfellow, “The Wreck of the Hesperus”, in Ballads and Other Poems
   But at that moment he is sprung upon by a panther billow leaping over the bulwarks. Wave after wave thus leaps into the ship […] 1851, Herman Melville, Moby Dick, Chapter 9
   The banners outflame the blazing morn, / O'er billows of bayonet, sword, and spear. 1864, Frank Moore, Songs of the Soldiers, page 238
   And the brooklet has found the billow / Though they flowed so far apart. 1873, Henry Wadsworth Longfellow, “The Brook and the Wave”, in Birds of Passage
   1893 August, Rudyard Kipling, "Seal Lullaby", in "The White Seal", National Review. Where billow meets billow, there soft be thy pillow; / Ah, weary wee flipperling, curl at thy ease!
   Have the swirling sands engulfed them, on a noon of storm when the desert rose like the sea, and rolled its tawny billows on the walled gardens of the green and fragrant lands? 1922, Clark Ashton Smith, The Caravan

verb

1. To surge or roll in billows.
   During the preceding afternoon a heavy North Pacific fog had blown in … Scudding eastward from the ocean, it had crept up and over the redwood-studded crests of the Coast Range mountains, […], billowing steadily eastward, it had rolled up the western slopes of the Siskiyou Range, […] 1920, Peter B. Kyne, chapter 2, in The Understanding Heart
   The black clouds of mercury vapour constantly billowing from the hatter's workshops and out into the streets must have been a horrifying sight. 2015, Alison Matthews David, Fashion Victims: The Damages of Dress Past and Present, page 59
2. To swell out or bulge.
   She had changed her auburn hair. Instead of wearing it in a billowing puff over her brow, she had gathered it into a ponytail, secured with a length of yellow yarn. 1983, Peter De Vries, chapter 9, in Slouching Towards Kalamazoo, page 125