bumble[verb]Synonyms: hum, bombinate, bum, buzz, drone, sowf, strum, thrum
[verb]Synonyms: botch, blow, blunder, bobble, bollix, bungle, fumble, mucker, muff, screw (up), stumble, lurch, snapper
 [TahlilGaran] English Synonym Dictionary ▲
 bum‧ble /ˈbʌmb
əl/ 
 verb [intransitive][
Date: 1500-1600; 
Origin: Probably from bungle]
1.  (
also bumble on) to speak in a confused way, so that no one can understand you: 
 What was Karl bumbling on about?2.
 What was Karl bumbling on about?2.  (
also bumble around) to move in an unsteady way 
 [TahlilGaran] Dictionary of Contemporary English ▲