Final answer:
A work stoppage by employees in support of another bargaining unit or union, despite having no dispute with their own employer, is known as a sympathy strike.
Step-by-step explanation:
A work stoppage by employees who have no dispute with their own employer but are striking in support of another bargaining unit or a union representing employees of another employer is called a sympathy strike. This term is used to describe a situation where workers stand in solidarity with other workers who are in the midst of a labor dispute, to help them achieve better working conditions or wage increases. This type of industrial action highlights the collective nature of labor movements and unions, emphasizing unity and mutual support among workers.