casual labor

Definition from Nolo’s Plain-English Law Dictionary

Sometimes used to refer to work that does not further the business of the employer, typically on a one-time or very sporadic basis. For example, someone who was hired for one day to clean the windows of a car showroom or a group that was hired for a few hours to unload new office furniture might be referred to as casual labor. Casual labor is not a legally recognized category, however: Workers performing casual labor are either independent contractors or employees, and the hiring company's legal and tax obligations to workers performing casual labor are the same as for other workers.

Definition provided by Nolo’s Plain-English Law Dictionary.