I. adjective
Usage: usually capitalized both Ms
1. : not to be taken seriously
switch to Mickey Mouse courses, where you don't work too hard — Willie Cager
these races are viewed as Mickey Mouse events featuring out-of-shape World Cup skiers who come for the appearance money — W.O.Johnson
also : not effectual : worthless
a Mickey Mouse lock
Mickey Mouse bookkeeping
2. : being or performing insipid or corny popular music
3. : of little importance : trifling
Mickey Mouse losses
: petty
Mickey Mouse regulations
II. noun
Usage: usually capitalized both Ms
: something that is Mickey Mouse
eliminating the Mickey Mouse from the soldier's routine — L.J.Binder