faithful
Meaning
remaining loyal and steadfast
true to the facts or the original
(the faithful) those who are faithful to a particular religion or political party
Structure
Usage
he has been a faithful friend for over thirty years.
the movie is a faithful adaptation of the classic novel.
the party's policies are designed to appeal to the faithful.
Etymology
the word 'faithful' is a compound formed within english from the noun 'faith' and the adjectival suffix '-ful'. the noun 'faith' itself has a long journey, originating from the latin 'fidēs', meaning trust, confidence, or belief, which is derived from the proto-indo-european root bʰeydʰ-, meaning 'to trust, confide, persuade'. the suffix '-ful' descends from the old english '-full', an adjective suffix literally meaning 'full of'. therefore, the literal construction 'full of faith' or 'characterized by faith' logically evolved to describe someone or something that is loyal, steadfast, or accurate to an original, perfectly capturing the modern abstract senses of loyalty and fidelity.
Analysis
faith (from latin 'fidēs' via old french 'feid', meaning trust, belief); ful (from old english '-ful', an adjective-forming suffix meaning 'full of' or 'characterized by').