stalwart

Concise Oxford English Dictionary © 2008 Oxford University Press:
stalwart /ˈstɔːlwət, ˈstal-/

▶adjective

• 1 loyal, reliable, and hard-working.

• 2 dated sturdy.

▶noun a stalwart supporter or participant in an organization.

– derivatives
stalwartly adverb,
stalwartness noun.

– origin ME: Scots var. of obs. stalworth, from OE stǣl ‘place’ + weorth ‘worth’.