I had to look that one up
stal·wart
/ˈstôlwərt/

adjective
adjective: stalwart

loyal, reliable, and hardworking.
"he remained a stalwart supporter of the cause"
h
Similar:
staunch
loyal
faithful
committed
devoted
dedicated
dependable
reliable
steady
constant
trusty
hard-working
vigorous
stable
firm
steadfast
redoubtable
resolute
unswerving
unwavering
unhesitating
unfaltering
h
Opposite:
disloyal
unfaithful
unreliable
dated
strongly built and sturdy.
"he was of stalwart build"

noun
noun: stalwart; plural noun: stalwarts

a loyal, reliable, and hardworking supporter or participant in an organization or team.
"the stalwarts of the Ladies' Auxiliary"