From Black's Law Dictionary

Service Defined.

​​​​​​​Contracts. Duty or labor to be rendered by one person to another, the former being bound to submit his will to the direction and control of the latter.

The act of serving the labor performed or the duties required.

Occupation, condition, or status of a servant, etc.

Performance of labor for benefit of another, or at another's command; attendance of an inferior, hired helper, etc.

Labor Defined:

Labor. Work; toil; service;