The name Pelasgians (Πελασγοί, Pelasgoí, singular: Πελασγός, Pelasgós) was used by classical Greek writers to refer either to the predecessors of the Greeks, or to all the inhabitants of Greece before the emergence of the Greeks. In general, "Pelasgian" has come to mean more broadly all the indigenous inhabitants of the Aegean Sea region and their cultures, "a hold-all term for any ancient, primitive and presumably indigenous people in the Greek world".
During the classical period, enclaves under that name survived in several locations of mainland Greece, Crete, and other regions of the Aegean. Populations identified as "Pelasgian" spoke a language or languages that at the time Greeks identified as "barbarian", though some ancient writers nonetheless described the Pelasgians as Greeks. A tradition also survived that large parts of Greece had once been Pelasgian before being Hellenized. These parts fell largely, though far from exclusively, within the territory which by the 5th century BC was inhabited by those speakers of ancient Greek who were identified as Ionians and Aeolians.
Much like all other aspects of the "Pelasgians", their ethnonym (Pelasgoi) is of extremely uncertain provenance and etymology. Michael Sakellariou collects fifteen different etymologies proposed for it by philologists and linguists during the last 200 years, though he admits that "most [...] are fanciful".
An ancient etymology based on mere similarity of sounds linked pelasgos to pelargos ("stork") and postulates that the Pelasgians were migrants like storks, possibly from Arcadia, where they nest. Aristophanes deals effectively with this etymology in his comedy The Birds. One of the laws of "the storks" in the satirical cloud-cuckoo-land, playing upon the Athenian belief that they were originally Pelasgians, is that grown-up storks must support their parents by migrating elsewhere and conducting warfare.
Gilbert Murray summarized the derivation from pelas gē ("neighboring land"), current at his time: "If Pelasgoi is connected with πέλας, 'near', the word would mean 'neighbor' and would denote the nearest strange people to the invading Greeks".