household deity

noun2

1. •
   A minor tutelary deity watching over a household, usually conceived as a protective ancestral spirit or genius loci.

   • […] Ganesh (Pillayar in Tamil), here is not associated with militant Hinduism; Pillayar is a lovable household deity here, a free and familiar god who craves no chauvinistic devotion. — 1990
2. •
   (figurative) An icon or patron saint: a revered individual within a group.

   • Sigmund Freud has replaced Darwin and/or Hegel as the household deity of sterilization. — 1967