Definition of one's name is mud in US English:

one's name is mud

phrase

informal
  • One is in disgrace or unpopular.

    ‘if you forget their birthdays, your name is mud’
    • ‘He likely realizes his name is mud around the Defense Department these days.’
    • ‘Then along comes the county courthouse, talking about running up a $232 million tab, and all of a sudden your name is mud.’
    • ‘I've got a load of cataloguing to do, then I'll be up all night unpacking the artifacts that had better arrive tomorrow or my name is mud.’
    • ‘Listen to me young lady, if you don't bring those grades up by the next test or quiz in those subjects then your name is mud.’
    • ‘I forgot to get him a little gift so now my name is mud.’