'Mainstay' definitions:

Definition of 'mainstay'

noun

A prominent supporter; "he is a pillar of the community" [syn: pillar, mainstay]

noun

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" [syn: anchor, mainstay, keystone, backbone, linchpin, lynchpin]

noun

The forestay that braces the mainmast

Definition of 'Mainstay'

From: GCIDE

Mainstay \Main"stay`\, n.
1. (Naut.) The stay extending from the foot of the foremast to the maintop. [1913 Webster]
2. Main support; principal dependence. [1913 Webster]
The great mainstay of the Church. --Buckle. [1913 Webster]

Synonyms of 'mainstay'

From: Moby Thesaurus

abettor,
admirer,
advocate,
afford support,
aficionado,
alpenstock,
angel,
apologist,
arm,
athletic supporter,
back,
back up,
backbone,
backer,
backing,
bandeau,
bear,
bear up,
bearer,
bolster,
bolster up,
bra,
brace,
bracer,
bracket,
brassiere,
buff,
bulwark,
buoy up,
buttress,
cane,
carrier,
carry,
cervix,
champion,
corset,
cradle,
crook,
crutch,
cushion,
defender,
dependence,
encourager,
endorser,
exponent,
fan,
favorer,
foundation garment,
friend at court,
fulcrum,
girdle,
give support,
guy,
guywire,
hold,
hold up,
jock,
jockstrap,
keep afloat,
keep up,
lend support,
lover,
Maecenas,
main strength,
maintain,
maintainer,
mast,
neck,
paranymph,
partisan,
patron,
pillar,
pillow,
promoter,
prop,
protagonist,
reinforce,
reinforcement,
reinforcer,
reliance,
rest,
resting place,
rigging,
second,
seconder,
sectary,
sheet anchor,
shore,
shore up,
shoulder,
shroud,
sider,
sinews,
spine,
sponsor,
sprit,
staff,
stalwart,
standby,
standing rigging,
stave,
stay,
stick,
stiffener,
strengthener,
subsidize,
subvention,
support,
supporter,
sustain,
sustainer,
sympathizer,
underbrace,
undergird,
underlie,
underpin,
underset,
upbear,
uphold,
upholder,
upkeep,
votary,
walking stick,
well-wisher