\By"-blow`\, n.
1. A side or incidental blow; an accidental blow.
         With their by-blows they did split the very stones
         in pieces.                            --Bunyan.
2. An illegitimate child; a bastard.
         The Aga speedily . . . brought her [his disgraced
         slave] to court, together with her pretty by-blow,
         the present Padre Ottomano.           --Evelyn.