Is “Sandbox” a Scrabble word?
Yes
SANDBOX
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Sandbox
/ˈsændbɒks/
noun
1.A children's play area consisting of a box filled with sand.
2.A box filled with sand that is shaped to form a mould for metal casting.
3.A container for sand or pounce, used historically before blotting paper.
Synonyms: sandpit
verb
1.To restrict (a program, etc.) by placing it in a sandbox.