Verb (used without object) : to mumble on a crust.    From Dictionary.com. 

Verb (used with object) : He mumbled something about expenses.    From Dictionary.com. 

I thought I saw McCain mumbling ... as well as stumbling and bumbling.    From Wordnik.com.  [Your Right Hand Thief] Reference

` ` I didn't know what that meant, but I guess I know now that mumbling is good.    From Wordnik.com.  [USATODAY.com - Basketball - Orlando vs. Detroit] Reference

Even though Science is moving rapidly forward always keep one eye on the mumbling from the shadows.    From Wordnik.com.  [The Language of Science – it’s “just a theory”] Reference

When an act billed as the Muneca Viviente was announced, I heard some mumbling from the audience behind me.    From Wordnik.com.  [Atayde Hermanos Circus] Reference

"It's telling that Twitter was translated as 'mumbling' in Japanese," he said.    From Wordnik.com.  [Twitter Scores Big In Japan As Millions 'Mumble' Online] Reference

She was wandering the streets, kind of mumbling to herself, trying to bum cigarettes from strangers.    From Wordnik.com.  [CNN Transcript Jul 12, 2004] Reference

He was "mumbling" as if using a telephone, said Mr Ferri.    From Wordnik.com. Reference

And I really don't know where you get the "mumbling" part.    From Wordnik.com.  [Entertainment Weekly's PopWatch] Reference

Twitter a hit in Japan as 'mumbling' tweeters give micro-blogging a distinctly Japanese flavor.    From Wordnik.com.  [Gaea Times (by Simple Thoughts) Breaking News and incisive views 24/7] Reference

A 2GB reporter said that, at the hospital, Mr Neale looked very haggard and had answered questions "mumbling".    From Wordnik.com.  [The Canberra Times] Reference

"mumbling" in Japan, and how it's taking Japanese culture by storm.    From Wordnik.com.  [All About The Music] Reference

Instead, he slunk mumbling in the other direction.    From Wordnik.com.  [Obama’s Moral Cowardice] Reference

We saw lots of people pacing, mumbling to themselves.    From Wordnik.com.  [An Unblinking Look at Suicide] Reference

I stopped short, mumbling the remnant of my sentence.    From Wordnik.com.  [The French Immortals Series — Complete] Reference

Newtondidn't have a clue what I was mumbling about, or whom.    From Wordnik.com.  [Lynda, The First] Reference

 Rousted, he wandered out into the hall mumbling to himself.    From Wordnik.com.  [Only a Memory Away] Reference

There were voices, too, as if some one was mumbling to himself.    From Wordnik.com.  [Army Letters from an Officer's Wife, 1871-1888] Reference

I consider mumbling “Tough break, Phil,” but think better of it.    From Wordnik.com.  [What We Can't Do] Reference

           He was mumbling to himself almost non-stop now.    From Wordnik.com.  [Wild Dreams of Reality, 6] Reference

He headed for the bedroom, mumbling that he was going to get some cash.    From Wordnik.com.  [Secrets of a Serial Killer] Reference

 Her husband, my friend, mumbling and grumbling, climbs back into bed.    From Wordnik.com.  [Minnesota Menage] Reference

  I must have been drifting off, mumbling to myself in drunken reverie.    From Wordnik.com.  [Ukiyo] Reference

Gus was mumbling, “The boy ... the boy,” and pushing the mask from his face.    From Wordnik.com.  [The Lookout] Reference

After some stunned mumbling, I say, This is going to be embarrassing to both of us.    From Wordnik.com.  [Kinsley's Revenge] Reference

And in fact, very Bob Dylan (mumbling) - you can't actually hear a word he's saying.    From Wordnik.com.  [Monty Python Vet Eric Idle: 'Not The Messiah'] Reference

At half past seven the Backslid Baptist on the leather seat began mumbling to himself.    From Wordnik.com.  [Lady Luck] Reference

She only comes out at night and is always mumbling funny words that nobody understands.    From Wordnik.com.  [From Beyond] Reference

I began, slowly, nearly mumbling, to read aloud from the next page - just ahead of him.    From Wordnik.com.  [Murakami on the Train] Reference

Do you start mumbling excuses or carry on as though everything was fine and hope for the best?.    From Wordnik.com.  [Are You Okay?] Reference

I hadn't said a mumbling word to her at the conference, did not know what her voice sounded like.    From Wordnik.com.  [End of the Affair] Reference

With a full load of passengers, I'd step on it and find myself mumbling, "When you get around to it, that is.".    From Wordnik.com.  [It's No Lawn Mower] Reference

Preparing his "victory" speech in Iowa, he sat alone on his hotel bed scribbling his lines, mumbling them aloud to himself.    From Wordnik.com.  [Mr. Smooth &Amp; Mr. Rough] Reference

After mumbling something about coming right back, he disappears, leaving his youngsters -- ages 4 and 6-planted at some computer game.    From Wordnik.com.  [Stealth Baby-Sitting] Reference