Is “Supplement” a Scrabble word?
Yes
SUPPLEMENT
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 Supplement
/ˈsʌpləmənt/
noun
1.Something added, especially to make up for a deficiency.
2.An extension to a document or publication that adds information, corrects errors or brings up to date.
3.An additional section of a newspaper devoted to a specific subject.
Synonyms: addition
verb
1.To provide or make a supplement to something.
Synonyms: eke out