Is heavy a word in the Scrabble Dictionary

Yes, heavy is playable

...and is worth 13 points.

Found in the following dictionaries

Enable (Words with friends)
SOWPODS (Collins Scrabble Words)
OTCWL2014 (NASPA Word List 2014)
TWL06 (NASPA List 2006)

"Heavy" Definition

noun

A serious or tragic role in a play.
An actor playing such a role.
Slang A mobster.
Slang A villain in a story or play.
Slang One that is very important or influential: a media heavy.

adjective

Broad or coarse: drew the face with heavy lines.
Dense; thick: a heavy fog.
Emotionally weighed down; despondent: a heavy heart.
Equipped with massive armaments and weapons: a heavy cruiser; heavy infantry.
Full of clay and readily saturated: heavy soil.

adverb

Heavily: The snow is falling heavier tonight than last night.
In a heavy manner .