Linguists use the term Aeolic to describe a set of rather archaic Greek sub-dialects, spoken mainly in Boeotia (a region in Central Greece), in Lesbos (an island close to Asia Minor) and in other Greek colonies.

It is probable that the Aeolic speakers represent the second (i.e. Achaean) migratory wave of Greeks (Hellenes) from the plains of Central Europe (or, according to other opinions, from what is present-day Ukraine) into their current homeland.

The so-called "Aeolic dialect" shows many archaisms, in comparison to the other Greek dialects (i.e. Ionian-Attic, Doric, Northwestern and Arcado-Cypriot), as well as many innovations, too.

The main traits of the Aeolic dialect are the following:

• The original Indo-european (and Proto-Greek) labiovelar [qw] turned everywhere in [p], a trait which finds its exact counterpart in the so-called P-Celtic languages (Welsh, Breton, Cornish, Ancient Gaulish etc.) and in some Italic languages, for example Oscan (an extinct language of Italy). This trait may point to an especially close relationship between Greek (Hellenic), Celtic and Italic branches of Indo-european linguistic family. [example: Ionic-Attic ti ? (=what?) < IE *qwid? > Aeolic pi?]
• The original Indo-european (and Proto-Greek) long a [a:] was retained everywhere, in contrast to the Ionic-Attic dialect, which turned it in a long open e [e:] under specific circumstances. [example: Ionic-Attic me:te:r (=mother) < IE *ma:te:r > Aeolic ma:te:r]
• The Aeolic dialect made extensive use of the so-called "athematic" verb conjugation, i.e. the conjugation ending in -mi. The same is also found in Irish, where this selection has been generalized (i.e -im). [example: Ionic-Attic phil(e)o: (=to love), Aeolic phile:mi]
• In many Aeolic sub-dialects (e.g. in that of Lesbos island), the word-stress was transferred in the first (or antepenultimate) syllable. This or similar traits are also found in many other Indo-european languages, such as Germanic, Italic, Insular Celtic, Croatian etc. [example: Ionic-Attic potamo's (= a river), Lesbian po'tamos]
• The infinitive ending of the Aeolic dialect is -men, the same as the Latin verbal nouns ending -men. This is easily explained by the fact that, in the Indo-european proto-language, the infinitive was mainly used as a verbal noun. [example: Ionic-Attic agein (= to lead, to do), Aeolic agmen]
• In Lesbian Aeolic, the phenomenon of "psilosis" occurred, as in the Ionic sub-dialect. By this term is meant the absence of the hard aspiration of initial vowels. [example: Attic he:lios (= sun), Ionic e:elios, Lesbian a:elios]
• In Boeotian the ancient Indo-european (and Proto-Greek) semi-vowel [w] or "digamma" was retained, as was also in the Doric dialect. [example: Ionic-Attic epos (=epos, word, epic poem), Boeotian wepos, Doric wepos]
• In Boeotian the vowel-system was in many cases changed in a way which reminds of the modern Greek pronunciation. [example: Ionic-Attic lyetai (=he/she unties him/herself), Boeotian lyete, Modern Greek linete]
• The original Indo-european consonant cluster -sm- was turned in -mm-, as in Gaulish, and not in -im-, as, say, in Ionic-Attic. [example: Ionic-Attic eimi (= I am), Aeolic emmi, Gaulish immi].