Definition of muso in US English:

muso

nounPlural musos

British
informal
  • 1A musician, especially one overly concerned with technique.

    ‘mixing genres allows the muso to show off’
    • ‘As part of the concept guest musos and instrumentalists are always welcome.’
    • ‘For four years she spent her days with the orchestra and her nights playing in clubs, doing recording sessions and working as a session muso.’
    • ‘It's all there, plus the maturity, vision and lyricism that you would expect from a bunch of serious musos, for whom this is their second album.’
    • ‘Ridiculed by musos for not being a ‘serious’ instrument, the concertina is nonetheless a perfect street companion: portable, polyphonic and loud enough to be heard above the urban din.’
    • ‘It also supports school bands and gives young musicians the chance to perform with more experienced musos.’
    1. 1.1 An avid music fan, especially one who has expensive stereo equipment.
      ‘prices way beyond the means of average musos’
      • ‘Ask your average muso and they will say that these boys from Seattle were the Godfathers of Grunge, purveyors of bile-built emotionally charged music of such rare quality that they became instant legends and timeless wonders.’
      • ‘I am fascinated by record shops - full of know-it-all shop assistants in teeshirt uniforms, and musos deeply into their thing.’
      • ‘Live jazz every Thursday night brings in a regular crowd of musos, while great coffee and snacks complete the picture.’
      • ‘Four part harmonies, a production quality that worked your stereo into a sweat and enough influences on display to have your average muso digging through their collection meant that the CD was never far away from a play.’

Origin

1960s (originally Australian): abbreviation.

Pronunciation

muso

/ˈmyo͞ozō//ˈmjuzoʊ/