Yes, boil 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)
"Boil" Definition
noun
A painful, circumscribed pus-filled inflammation of the skin and subcutaneous tissue usually caused by a local staphylococcal infection. Also called furuncle.
An agitated, swirling, roiling mass of liquid: "Those tumbling boils show a dissolving bar and a changing channel thereā ( Mark Twain).
Lower Southern U.S. A picnic featuring shrimp, crab, or crayfish boiled in large pots with spices, and then shelled and eaten by hand.
The condition or act of boiling.
A localized swelling and inflammation of the skin resulting from infection of a hair follicle and adjacent tissue, having a hard central core, and forming pus.
phrasal-verb
Boil down To condense; summarize: boiled down the complex document.
Boil down To constitute the equivalent of in summary: The scathing editorial simply boils down to an exercise in partisan politics.
Boil down To reduce in bulk or size by boiling.
Boil over To overflow while boiling.
verb-intransitive
To be in a state of agitation; seethe: a river boiling over the rocks.
To be stirred up or greatly excited: The mere idea made me boil.
To change from a liquid to a vapor by the application of heat: All the water boiled away and left the kettle dry.
To reach the boiling point.
To undergo the action of boiling, especially in being cooked.
verb-transitive
To cook or clean by boiling.
To heat to the boiling point.
To separate by evaporation in the process of boiling: boil the maple sap.
To vaporize (a liquid) by the application of heat.
verb
To generate bubbles of vapor when heated .
To cook in boiling water.
To be moved, excited, or stirred up.