In the Arabian Peninsula, lexically diminutive personal names, family names and place names are ubiquitous. In a dataset of 9,060 Arabian names, 1,717 (19 per cent) are diminutive. This article finds that the diminutive pattern CiCēC (cf. Classical CuCayC) has meanings and functions in Arabic names that are distinct from its meanings and functions in common nouns. In addition to expected meanings related to size, the diminutive carries partitive and attributive meanings. It may simply mark a name (as an onymic) or derive a name (as a transonymic). The diminutive may disambiguate two similar names found in close proximity (e.g. Diba ≠ Dubai). The form and function of the diminutive differ categorically according to what kind of name is diminutivized, supporting the semantic-pragmatic theory of names. A quantitative analysis of toponyms indicates that diminutive names are associated with Bedouin dialects and practices, as suggested by previous research.