Semitic is an adjective referring to the peoples who have traditionally spoken Semitic languages or to things pertaining to them. The negative form anti-Semitic, however, is almost always used to mean "anti-Jewish" specifically. Genetic analysis suggests that the Semitic peoples share a significant common ancestry, despite important differences and contributions from other groups. The word derives from Shem, one of the three sons of Noah.
The concept of a "Semitic" people is derived from Biblical accounts of the origins of the cultures known to the ancient Hebrews. Those closest to them in culture and language were generally deemed to be descended from Shem. Enemies were often said to be descendents of his cursed brother Ham. In Genesis Shem is described as the father of the Assyrians, Chaldeans, Aramaeans, Sabaeans, and Hebrews, all of whose languages are closely related; the linguistic family containing them was therefore named Semitic by linguists. However, the Canaanites and Amorites also spoke a language belonging to this family, and are therefore also termed Semitic in linguistics despite being described in Genesis as sons of Ham (See Sons of Noah). Shem is also described in Genesis as the father of the Elamites and the far-eastern descendants of Lud, whose languages were not Semitic. In Medieval Europe all Asian peoples were thought of as descendents of Shem.
The modern linguistic meaning of "Semitic" is therefore derived from, but not identical to Biblical usage. In a linguistic context the Semitic languages include, among others, Arabic, Hebrew, Canaanite, Akkadian, and Amharic. Some of the peoples who spoke these languages were descendants of the Phoenicians, which was the Greek name for the Canaanites. At the height of the Carthaginian empire, Semitic languages would have been widely spoken all the way along the southern Mediterranean Sea to the Atlantic Ocean. Semitic languages are also spoken in Malta and on Socotra in the Indian Ocean. Additionally, millions of Muslims speak Classical (Qur'anic) Arabic as a second language, and many Jews all over the world speak Hebrew as a second language. It should be noted that Coptic, Berber, Somali, and many other related Afro-Asiatic languages within this area do not belong to the Semitic subgroup.
In a religious context, the term Semitic can refer to the religions associated with the speakers of these languages: thus Judaism, Christianity, and Islam are often described as "Semitic religions", though the term Abrahamic religions is more common today. A truly comprehensive account of "Semitic" religions would equally include the polytheistic religions (such as the religions of Tammuz or Adad) that flourished in the Middle East before the Abrahamic religions.
Outside linguistics, the term's primary use in modern times is to refer to the ethnic groups who have historically spoken Semitic languages. The best way known to test an ethnic group's common physical descent is through genetic research. Though in genetic research no significant common mitochondrial results have been yielded, genetic Y-chromosome links between Near-Eastern peoples like the Palestinians, Syrians and ethnic Jews have proved fruitful (see Y-chromosomal Aaron). While population genetics is still a young science, it seems to indicate that a significant proportion of these peoples' ancestry comes from a common Near-Eastern population to which (despite the differences with the Biblical genealogy) the term Semitic has been applied.