by-blow

• byblow, bye-blow

From by- +‎ blow.

• (UK) IPA^(key): /ˈbʌɪbləʊ/

by-blow (plural by-blows)

1. A blow struck to the side or from the side, as in swordplay; a secondary or incidental strike of any sort.
   • 1910, Arthur Quiller-Couch, "The Copernican Convoy," in Corporal Sam and Other Stories,

     Either commander took speedy advantage of it—Hopton to make a swift diversion into Sussex and capture Arundel Castle (which was but a by-blow, for in a few weeks he had lost it again).

   • 2009, Diarmaid MacCulloch, A History of Christianity, Penguin 2010, p. 732:

     As a by-blow in the course of his relentless campaigns against Louis, Willem gained the three thrones of Britain in 1699 – but what a by-blow this proved!

2. An illegitimate child; a child of an unknown or unmarried father.
   • 1749, Henry Fielding, Tom Jones, Folio Society 1973, p. 275,

     ‘Nay,’ said the landlady, ‘if I thought he was a gentleman's son, thof he was a bye-blow, I should behave to him in another guess manner; for many of these bye-blows come to be great men, and, as my poor first husband used to say, never affront any customer that's a gentleman.’

   • c. 1892, Herman Melville, "Billy Budd, Foretopman" (novella), in Herman Melville: Selected Tales and Poems, Holt, Rinehart & Winston (1950), p. 298,

     Yes, Billy was a foundling, a presumable bye-blow, and, evidently, no ignoble one.

   • 1971, Brad Darrach, "Knee-High to Ezra Pound," Time, 2 Aug.,

     The best hope has been that friends and family would talk, a hope partly realized in this discreet but perceptive memoir by his illegitimate daughter. . . . Little Mary was a by-blow and an inconvenience.

• (illegitimate child): bastard, see also Thesaurus:bastard

• by-blow in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.
• Oxford English Dictionary, 2nd ed., 1989.

• Bowlby, Wobbly, blow-by, blowby, wobbly