Is “Filament” a Scrabble word?
Yes
FILAMENT
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 Filament
/ˈfɪləmənt/
noun
1.A fine thread or wire.
2.Such a wire, as can be heated until it glows, in an incandescent light bulb or a thermionic valve.
3.A massive, thread-like structure, such as those gaseous ones which extend outward from the surface of the sun, or such as those (much larger) ones which form the boundaries between large voids in the universe.
“galaxy filament”