casual

A worker who is only working for a company occasionally, not as its permanent employee.

A soldier temporarily at a place of duty, usually en route to another place of duty.

A member of a group of football hooligans who wear expensive designer clothing to avoid police attention; see casual (subculture).

One who receives relief for a night in a parish to which he does not belong; a vagrant.

Happening by chance.

"They only had casual meetings."

Coming without regularity; occasional or incidental.

"The purchase of donuts was just a casual expense."

Employed irregularly.

"He was just a casual worker."

Careless.