During the classical period, the Romans interacted with, and later conquered, parts of Mauretania, a state that covered modern northern Morocco, western Algeria, and the Spanish cities Ceuta and Melilla. The Berber tribes of the region were noted in the Classics as Mauri, which was subsequently rendered as "Moors" in English and in related variations in other European languages. Mauri (Μαῦροι) is recorded as the native name by Strabo in the early 1st century. This appellation was also adopted into Latin, whereas the Greek name for the tribe was Maurusii (Ancient Greek: Μαυρούσιοι). The Moors were also mentioned by Tacitus as having revolted against the Roman Empire in 24 AD.
During the Latin Middle Ages, Mauri was used to refer to Berbers and Arabs in the coastal regions of Northwest Africa.  The 16th century scholar Leo Africanus (c. 1494–1554) identified the Moors (Mauri) as the native Berber inhabitants of the former Roman Africa Province (Roman Africans). He described Moors as one of five main population groups on the continent alongside Egyptians, Abyssinians (Abassins), Arabians and Cafri (Cafates).
In medieval Romance languages, variations of the Latin word for the Moors (for instance, Italian and Spanish: moro, French: maure, Portuguese: mouro, Romanian: maur) developed different applications and connotations. The term initially denoted a specific Berber people in western Libya, but the name acquired more general meaning during the medieval period, associated with "Muslim", similar to associations with "Saracens". During the context of the Crusades and the Reconquista, the term Moors included the derogatory suggestion of "infidels".
Apart from these historic associations and context, Moor and Moorish designate a specific ethnic group speaking Hassaniya Arabic. They inhabit Mauritania and parts of Algeria, Western Sahara, Tunisia, Morocco, Niger, and Mali. In Niger and Mali, these peoples are also known as the Azawagh Arabs, after the Azawagh region of the Sahara.
The authoritative dictionary of the Spanish language does not list any derogatory meaning for the word moro, a term generally referring to people of Maghrebian origin in particular or Muslims in general. Some authors have pointed out that in modern colloquial Spanish use of the term moro is derogatory for Moroccans in particular and Muslims in general.
In the Philippines, a former Spanish colony, many modern Filipinos call the large, local Muslim minority concentrated in Mindanao and other southern islands Moros. The word is a catch-all term, as Moro may come from several distinct ethno-linguistic groups such as the Maranao people. The term was introduced by Spanish colonisers, and has since been appropriated by Filipino Muslims as an endonym, with many self-identifying as members of the Bangsamoro "Moro Nation".
Moreno can mean "dark-skinned" in Spain, Portugal, Brazil, and the Philippines. Also in Spanish, morapio is a humorous name for "wine", especially that which has not been "baptized" or mixed with water, i.e., pure unadulterated wine. Among Spanish speakers, moro came to have a broader meaning, applied to both Filipino Moros from Mindanao, and the moriscos of Granada. Moro refers to all things dark, as in "Moor", moreno, etc. It was also used as a nickname; for instance, the Milanese Duke Ludovico Sforza was called Il Moro because of his dark complexion.
In Portugal, mouro (feminine, moura) may refer to supernatural beings known as enchanted moura, where "Moor" implies "alien" and "non-Christian". These beings were siren-like fairies with golden or reddish hair and a fair face. They were believed to have magical properties. From this root, the name moor is applied to unbaptized children, meaning not Christian. In Basque, mairu means moor and also refers to a mythical people.
Muslims located in South Asia were distinguished by the Portuguese historians into two groups: Mouros da Terra ("Moors of the Land") and the Mouros da Arabia/Mouros de Meca ("Moors from Arabia/Mecca" or "Paradesi Muslims"). The Mouros da Terra were either descendants of any native convert (mostly from any of the former lower or untouchable castes) to Islam or descendants of a marriage alliance between a Middle Eastern individual and an Indian woman.
Within the context of Portuguese colonization, in Sri Lanka (Portuguese Ceylon), Muslims of Arab origin are called Ceylon Moors, not to be confused with "Indian Moors" of Sri Lanka (see Sri Lankan Moors). Sri Lankan Moors (a combination of "Ceylon Moors" and "Indian Moors") make up 12% of the population. The Ceylon Moors (unlike the Indian Moors) are descendants of Arab traders who settled there in the mid-6th century. When the Portuguese arrived in the early 16th century, they labelled all the Muslims in the island as Moors as they saw some of them resembling the Moors in North Africa. The Sri Lankan government continues to identify the Muslims in Sri Lanka as "Sri Lankan Moors", sub-categorised into "Ceylon Moors" and "Indian Moors".
The Goan Muslims — a minority community who follow Islam in the western Indian coastal state of Goa — are commonly referred as Moir (Konkani: मैर) by Goan Catholics and Hindus.[a] Moir is derived from the Portuguese word mouro ("Moor").