origin: (1910) Slang; Irish, via Old French muchier= hide, lurk or Germanic mitch= to steal.
Dialectical; to shirk, sneak, or hide -- like ditching school or loitering in order to pick-pocket. Implies cowardice and/or deliberately anti-social behavior.
"With Leo Dillon and a boy named Mahony I planned a day's miching." - James Joyce
See also, the oft debated Shakespearean expression from Hamlet: miching mallecho.