Spare

an extra component of a machine or other apparatus

an extra car wheel and tire for a four-wheel vehicle

a score in tenpins

refrain from harming

save or relieve from an experience or action

give up what is not strictly needed

use frugally or carefully

thin and fit

more than is needed, desired, or required

not taken up by scheduled activities

kept in reserve especially for emergency use

lacking in magnitude or quantity

lacking embellishment or ornamentation