Casual
noun
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).
adjective
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.”
Synonyms: accidental, fortuitous, incidental, occasional, random, unexpected, informal