Deity is from Old French deite, from Late Latin deitas ('divine nature'), coined by Augustine from Latin deus ('god'). The ancestry passes through Latin deitas, Latin deus, and Proto-Indo-European *deywós. In present use as a noun, it means "a god or goddess; divine nature", keeping the historical formation close to the word's ordinary semantic work. Related words include deify, deific, deism, and divine. Its contrast set includes mortal and human, which clarifies the semantic boundary of the modern word. The surrounding word family keeps the same base visible in deify, deific, deism, and divine, showing how the headword belongs to a larger cluster rather than standing alone.