Is “Mainstay” a Scrabble word?
Yes
MAINSTAY
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 Mainstay
/ˈmeɪn.steɪ/
noun
1.A chief support.
“Agriculture is the mainstay of this country’s economy.”
2.Someone or something that can be depended on to make a regular contribution.
3.A stabilising rope from the top of the mainmast to the bottom of the foremast.