Both Uses

minimum wage
in
Sycamore Row
(Auto-generated)

I got the impression she's a fairly typical black woman for these parts, with a houseful of kids, a part-time husband, a minimum-wage job, a hard life.†
p. 88.8 *

minimum-wage = lowest legal hourly pay
Minimum wage but that's all she can find right now.†
p. 404.9

Definitions:

(1) (minimum wage)
the lowest hourly pay rate that employers are legally allowed to pay workers

Minimum wage laws set a floor for wages so workers aren't paid extremely low amounts for their labor. In the U.S., there is a federal minimum wage, and many states and cities set higher minimum wages that employers must follow. Some jobs with tips (like servers) can have special rules. The term can also be used to describe a lowest wage set by a union.
(2) (meaning too rare to warrant focus)