peninsula south of Thrace, from Greek khersonesos "peninsula," from khersos "dry land" + nēsos "island," also "(flooded) land near a river, alluvial land," which is of uncertain origin; traditionally from PIE root sna- "to swim," but this is now generally rejected. "As words for 'island' differ from language to language, [nēsos] is probably an Aegean loan (note that Lat. insula is also of unclear origin)" [Beekes]. Compare isle.
federation comprising the southern end of the Malay peninsula (except Singapore) and the northwestern part of Borneo, from Malay + Latinate ending -ia. Originally an early 19c. British geographers' name for the Indonesian archipelago. Related: Malaysian.
"native of the Malay peninsula or the adjecent islands," also "the language of the Malays," 1590s, from native (Austronesian) name Malayu. As an adjective from 1779; the earlier adjective form was Malayan (1660s).
peninsula of southern Greece, from Latin, from Greek Peloponnēsos. The second element apparently is nēsos "island" (see Chersonese); the first element is said to be from Pelops, name of the son of Tantalus, who killed him and served him to the gods as food (they later restored him to life). The proper name is probably from pelios "gray, dark" (from PIE root *pel- (1) "pale") + ōps "face, eye" (from PIE root *okw- "to see"). But the association of the proper name with the peninsula name likely is folk etymology.
Related: Peloponnesian (late 15c. as a noun, "a native or inhabitant of the Peloponnesus"). The Peloponnesian War (1570s) was the great struggle for hegemony between Athens and her maritime empire and Sparta and her allies on the Peloponnesus, waged from 431 B.C.E. to 404 B.C.E.