Is “Sourcebook” a Scrabble word?
Yes
SOURCEBOOK
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 Sourcebook
noun
1.A book consisting of a collection of writings on a particular subject.
2.A publication intended to supplement the core materials of a roleplaying game.