The Collaborative International Dictionary of English v.0.48:
Blunder \Blun"der\, v. i. [imp. & p. p. Blundered; p. pr. &
vb. n. Blundering.] [OE. blunderen, blondren, to stir,
confuse, blunder; perh. allied to blend to mix, to confound
1. To make a gross error or mistake; as, to blunder in
writing or preparing a medical prescription. --Swift.
2. To move in an awkward, clumsy manner; to flounder and
I was never distinguished for address, and have
often even blundered in making my bow. --Goldsmith.
Yet knows not how to find the uncertain place,
And blunders on, and staggers every pace. --Dryden.
To blunder on.
(a) To continue blundering.
(b) To find or reach as if by an accident involving more
or less stupidity, -- applied to something desirable;
as, to blunder on a useful discovery.