Yes, what is playable
...and is worth 9 points.
Found in the following dictionaries
Enable (Words with friends)
SOWPODS (Collins Scrabble Words)
OTCWL2014 (NASPA Word List 2014)
TWL06 (NASPA List 2006)
"What" Definition
adjective
How great; how astonishing: What a fool!.
Whatever: They soon repaired what damage had been done.
Which one or ones of several or many: What college are you attending? You should know what musical that song is from.
How remarkable or striking for good or bad qualities.
The … that as much or as many … as.
adverb
How much; in what respect; how: What does it matter?.
pronoun
One of how much value or significance: What are possessions to a dying man?.
That which; the thing that: Listen to what I tell you.
Whatever thing that: come what may.
Which kind, character, or designation: What are these objects?.
Which thing or which particular one of many: What are you having for dinner? What did she say?.
idiom
What for Informal A scolding or strong reprimand: The teacher gave the tardy student what for.
What have you What remains and need not be mentioned: a room full of chairs, lamps, radios, and what have you.
What if What does it matter if.
What if What would occur if; suppose that.
What it takes The necessary expertise or qualities needed for success: She has what it takes to be a doctor.
interjection
Chiefly British Used as a tag question, often to solicit agreement.
Used to express surprise, incredulity, or other strong and sudden excitement.
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