This entry covers ὁ, ἡ, τό in its multiple overlapping functions across Greek dialects and historical periods. In Attic prose it served primarily as the definite article ('the'), a relatively late development in Greek. In Homer it could still function as a demonstrative ('this, that') or even as a relative pronoun ('who, which'). The forms show bewildering dialectal variation: different dialects preserved different case forms, particularly in dual and less common cases. Modern grammarians debate whether nominative forms were originally oxytone or unaccented. This word represents one of the most fundamental elements of Greek syntax, evolving from demonstrative origins to grammatical article, while retaining traces of older functions in poetry.