Is “Blacken” a Scrabble word?
Yes
BLACKEN
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 Blacken
/ˈblækən/
verb
1.(causative) To cause to be or become black.
2.To become black.
“The sky blackened as the storm clouds rolled in.”
3.(causative) To make dirty.
Synonyms: defame, denigrate, sully, taint, tarnish, black