Yes, spare is playable
...and is worth 8 points.
Found in the following dictionaries
Enable (Words with friends)
SOWPODS (Collins Scrabble Words)
OTCWL2014 (NASPA Word List 2014)
TWL06 (NASPA List 2006)
"Spare" Definition
noun
A replacement, especially a tire, reserved for future need.
Sports The act of knocking down all ten pins with two successive rolls of a bowling ball.
Sports The score so made.
A duplicate (as a key or a machine part) kept in reserve.
verb-transitive
To hold back from; withhold or avoid: spared no expense for the celebration.
To refrain from harming or destroying.
To refrain from treating harshly; treat mercifully or leniently.
To save or relieve from experiencing or doing (something): spared herself the trouble of going.
idiom
To spare In addition to what is needed: We paid our bills and had money to spare.
verb
To forbear to destroy, punish, or harm.
To refrain from attacking or reprimanding with necessary or salutary severity.
To relieve of the necessity of doing or undergoing something .
To use or dispense frugally .
adjective
Being in excess of what is needed; extra. See Synonyms at superfluous.
Free for other use; unoccupied: spare time.
Kept in reserve: a spare part; a spare pair of sneakers.
Lean and trim. See Synonyms at lean2.
Not lavish, abundant, or excessive: a spare diet.
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