The phrase "ancient dialect" is correct and usable in written English.
It can be used to refer to a language or form of speech that was used in the past and is no longer in common use today.
Example: "The researchers discovered an ancient dialect that was spoken by a long-lost civilization."
Alternatives: "archaic language" or "old dialect".
Few Mapuches speak their ancient dialect, and traditional Mapuche dress has mostly been discarded.
That was when the Scottish people collectively decided to christen the storm that raged across their fair land with their ancient dialect word for scrotum and disseminated it across Twitter and all other social media.
The name itself comes from an ancient dialect word for eerie and the wood is well-known for being home to a pack of hellhounds that hunt with a dark-robed figure, threatening to steal the mortal soul of anyone crazy enough to enter the area – otherwise it's perfectly safe.
It's a band of middle-aged men playing ethnic Mongolian music, singing in ancient dialects, with electric guitars, banjo, throat-singing and the morin khuur, a two-stringed, cello-size instrument; they use '70s rock grooves and their own modes and chants.
Most speak an ancient Hebrew dialect.
In this respect the very detailed knowledge of the Ancient Greek dialect situation is quite untypical.
Of the local dialects, Tsakonian, spoken in certain mountain villages in eastern Peloponnese, is quite aberrant and shows evidence of descent from the ancient Doric dialect (e.g., it often has an /a/ sound for the early Greek /ā/ that went to /ē/ in Attic, later to /i/).
Campani, the Roman name for the inhabitants of Capua and later those of the Campanian plain, is actually pre-Roman and appears with terminations (suffixes) inscribed in Oscan (an ancient Italic dialect) on coins struck for or by the Samnites, the conquerors of Campania in the late 5th century bc.
Part of the church's liturgy is said in an ancient Aramaic dialect believed to be closely related to the language spoken by Christ.
It is the birthplace of Thomas Hardy, who used the county as the principal setting of his novels, and William Barnes, whose poetry celebrates the ancient Dorset dialect.
Marluu is a "muxe," a term derived from the ancient Zapotec dialect to describe a community of gay men who date heterosexual men while dressing as women, sometimes assuming traditional female roles within the family and society.
