What is Flannie?
1.
Checkered shirts made out of flannelette, usually worn until old and ragged with jeans or khakis. Worn by working class people like builders, construction workers etc.
Where's me flannie shirt, love?
See
2.
Australian: A Flannelette checked shirt.
Bugger me sideways, me ciggers cost more than the flannie I tuck them into!
See