spare

not taken up by scheduled activities

“spare time on my hands”

a score in tenpins; knocking down all ten after rolling two balls

kept in reserve especially for emergency use

“a spare tire”

save or relieve from an experience or action

“I'll spare you from having to apologize formally”

use frugally or carefully

thin and fit

“the spare figure of a marathon runner”

refrain from harming

lacking embellishment or ornamentation

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

give up what is not strictly needed

“he asked if they could spare one of their horses to speed his journey”

more than is needed, desired, or required

“sleeping in the spare room”