1610s, "native or inhabitant of Malta;" 1797 (adj.) "of or pertaining to Malta, from Malta + -ese. Maltese cross is from 1754 (earlier Malta cross, 1650s), so called because it was worn by the Knights of Malta. Maltese cat is attested from 1830: any cat with fur completely or primarily gray or blue, supposedly a common trait among cats on the island, but the breeds that noted for this coloring are not associated with Malta. As a type of very small dog, known since ancient times in the Mediterranean, it is attested in English by 1803.

Strabo informs us, that "there is a town in Pachynus, a promontory of Sicily, (called Meleta,) from whence are transported many fine little dogs, called Melitae Canes. They were accounted the jewels of women; but now the said town is possessed by fishermen, and there is no such reckoning made of those tender little dogs, which are not bigger than common ferrets or weasels; yet are they not small in understanding, nor unstable in their love to men, for which cause they are also nourished tenderly for pleasure." [Capt. Thomas Brown, "Biographical Sketches and Authentic Anecdotes of Dogs," Edinburgh, 1829]

Definitions of Maltese
Maltese (n.)
a native or inhabitant of Malta;
Maltese (n.)
the national language of the Republic of Malta; a Semitic language derived from Arabic but with many loan words from Italian, Spanish, and Norman-French;
Synonyms: Maltese language / Malti
Maltese (n.)
a term applied indiscriminately in the United States to any short-haired bluish-grey cat;
Synonyms: Maltese cat
Maltese (n.)
breed of toy dogs having a long straight silky white coat;
Synonyms: Maltese dog / Maltese terrier
Maltese (adj.)
of or relating to the island or republic of Malta or its inhabitants;