Definition of messan in English:

messan

noun

Scottish
  • A small pet dog; a lapdog.

    ‘out came her wee messan’
    • ‘She takes the little messan dog to walk down by the shore.’
    • ‘It was a huge mastiff far too large to be her messan or lap dog.’
    • ‘She takes such care of me that she dogs my footsteps like a messan.’
    • ‘He reached the unfortunate messan, took him in his mouth, and carried him to the opposite bank.’
    • ‘Davie has no more presence than a messan dog.’

Origin

Late 15th century: from Scottish Gaelic measan, Irish measán ‘small dog’, diminutive of mess ‘favoured one’.