Relational nouns, or relator nouns, are a word class in many languages. They are characterized as functioning syntactically as nouns although they convey the meaning for which other languages use adpositions (prepositions and postpositions). In Mesoamerican languages, the use of relational nouns constitutes an areal feature of the Mesoamerican linguistic area, including the Mayan languages, Mixe–Zoquean languages, and Oto-Manguean languages.

Relational nouns are also widespread in Southeast Asia (e.g. Vietnamese, Thai), East Asia (e.g. Mandarin Chinese, Japanese, Lhasa Tibetan), Central Asia (e.g. the Turkic languages), Armenian, the Munda languages of South Asia (e.g. Sora), and in the Micronesian languages.

A relational noun is grammatically speaking a simple noun, but because its meaning describes a spatial or temporal relation, rather than a "thing", it describes location, movement, and other relations, just like prepositions in the languages that have them. When used, the noun is "owned" by another noun and describes a relation between its "owner" and a third noun. For example, one could say "the cup is the table its-surface", where "its surface" is a relational noun denoting the position of something standing on a flat surface. Here are examples:

Classical Nahuatl

Ca

Be

ī-pan

its-on