Yes, sound 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)
"Sound" Definition
noun
A distinctive noise: a hollow sound.
A long, relatively wide body of water, larger than a strait or a channel, connecting larger bodies of water.
A long, wide ocean inlet.
An instrument used to examine or explore body cavities, as for foreign bodies or other abnormalities, or to dilate strictures in them.
adjective
Based on valid reasoning: a sound observation. See Synonyms at valid.
Compatible with an accepted point of view; conservative.
Deep and unbroken; undisturbed: a sound sleep.
Financially secure or safe: a sound economy.
Free from defect, decay, or damage; in good condition.
verb-transitive
Linguistics To articulate; pronounce: sound a vowel.
To cause to give forth or produce a sound: sounded the gong.
To examine (a body organ or part) by causing to emit sound; auscultate.
To make known; celebrate: "Nations unborn your mighty names shall sound” ( Alexander Pope).
To measure the depth of (water), especially by means of a weighted line; fathom.
phrasal-verb
Sound off To count cadence when marching in military formation.
adverb
Thoroughly; deeply: sound asleep.
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