to use / to employ / to make use of, to apply / to spend

(formal) Female third-person singular pronoun; she, her, girlfriend

(colloquial) a girlfriend (a female partner in a romantic relationship)

(literary) they (about women or girls)

hot, warm (weather), heat

(of weather) hot, baking

use one thing for many purposes / work someone hard

to use one's head

(literary) they (about women or girls)

intense heat; hottest period in summer