Is “Zillionth” a Scrabble word?
Yes
ZILLIONTH
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 Zillionth
/ˈzɪljənθ/
noun
1.The person or thing in the zillionth position.
2.One of a zillion equal parts of a whole.
adjective
1.The ordinal form of the number zillion.