spare 
(spâr)
(spâr)tr.v. spared, spar·ing, spares
1.
a. To refrain from harming, injuring, destroying, or killing: The general spared the city from a bombardment.
b. To leave undamaged or unharmed: The oldest trees in the forest were spared from the fire.
c. To refrain from denouncing or distressing; treat leniently or with consideration: The teacher spared the student's feelings by not criticizing her.
d. To allow (someone) to avoid experiencing or doing (something): spared myself the trouble of going to the store.
2.
a. To hold back from; withhold or avoid: spared no expense for the celebration.
b. To use or supply with restraint: Don't spare the mustard.
3. To give or grant out of one's resources; afford: Can you spare ten minutes?
adj. spar·er, spar·est
1.
a. Kept in reserve: spare parts.
b. Being in excess of what is needed; extra: spare cash.
c. Free for other use; unoccupied: spare time.
2.
a. Not lavish, abundant, or excessive; meager: a spare breakfast.
b. Lean and trim: a runner with a spare figure.
c. Not elaborate or ornate; simple: a writer's spare style.
n.
Idiom: 1. A replacement, especially a tire, reserved for future need.
2. Sports
a. The act of knocking down all ten pins with two successive rolls of a bowling ball.
b. The score so made.
to spare
In addition to what is needed: We paid our bills and had money to spare.
[Middle English sparen, from Old English sparian.]
sparely adv.
spareness n.
sparer n.