Blundered

a gross, stupid, or careless mistake:
That’s your second blunder this morning.
to move or act blindly, stupidly, or without direction or steady guidance:
Without my glasses I blundered into the wrong room.
to make a gross or stupid mistake, especially through carelessness or mental confusion:
Just pray that he doesn’t blunder again and get the names wrong.
to bungle; botch:
Several of the accounts were blundered by that new assistant.
to utter thoughtlessly; blurt out:
He blundered his surprise at their winning the award.
Contemporary Examples

The 50th Anniversary of JFK’s Inauguration Evan Thomas January 14, 2011
Is the 2012 Election Finally Breaking Barack Obama’s Way? Howard Kurtz November 2, 2012
Many Candidates Are MIA in the 2012 Iowa Caucuses Howard Kurtz December 8, 2011
And You Thought U.S. Conservatives Were Out of Touch! Andrew Pierce November 6, 2008

Historical Examples

Indian and Scout F. S. Brereton
Ranald Bannerman’s Boyhood George MacDonald
Life of Lord Byron, Vol. 6 (of 6) Thomas Moore
A Singer from the Sea Amelia Edith Huddleston Barr
History of Linn County Iowa Luther A. Brewer
A Son of Hagar Sir Hall Caine

noun
a stupid or clumsy mistake
a foolish tactless remark
verb (mainly intransitive)
to make stupid or clumsy mistakes
to make foolish tactless remarks
often foll by about, into, etc. to act clumsily; stumble: he blundered into a situation he knew nothing about
(transitive) to mismanage; botch
v.
n.