Is “Tier” a Scrabble word?
Yes
TIER
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 Tier
/ˈtaɪ.ə(ɹ)/
noun
1.One who ties (knots, etc).
2.Something that ties.
3.A child's apron.