lodestar
/ˈləʊdstɑː
/noun
A star that is used to guide the course of a ship, especially the pole star: figurative she dominated his existence as chief muse and intellectual lodestar
Synonyms
guide, guiding star, guiding light, role model, model, luminary, exemplar, ideal, inspiration;
criterion, aim, guiding principle, standard, pattern
Origin
Middle English: from lode in the obsolete sense 'way, course' + star.