1.Definition: kept in reserve especially for emergency use

"A spare tire", "Spare parts"

2.Definition: lacking embellishment or ornamentation

Related Adjective(s):bare, plain, unembellished, unornamented

3.Definition: lacking in magnitude or quantity

"A spare diet"

Related Adjective(s):bare, scanty

4.Definition: more than is needed, desired, or required

"Sleeping in the spare room"

Related Adjective(s):excess, extra, redundant, supererogatory, superfluous, supernumerary, surplus

5.Definition: not taken up by scheduled activities

"Spare time on my hands"

Related Adjective(s):free

6.Definition: thin and fit

"The spare figure of a marathon runner"

Related Adjective(s):trim