mainstay

nouns

a prominent supporter
"he is a pillar of the community"
mainstay, pillar
a central cohesive source of support and stability
"faith is his anchor"; "the keystone of campaign reform was the ban on soft money"; "he is the linchpin of this firm"
anchor, backbone, keystone, linchpin, lynchpin, mainstay
the forestay that braces the mainmast
mainstay
is a type of (narrower)
an adjustable stay from the foremast to the deck or bowsprit; controls the bending of the mast
forestay