adessiveon

Adessiveon is a hypothetical linguistic concept used to describe a specialized locative relation that encodes direct contact with the surface on which an object rests, rather than merely being located on or near it. The term combines adessive, the locative case found in Finnic languages that marks a surface-on location, with the common suffix -on, used in discussions of morphology and conlang creation. In theoretical syntax and typology, adessiveon is proposed as a dedicated marker (suffix, clitic, or particle) that signals surface contact, allowing a language to distinguish between being on something and being on top with tangible contact.

In proposed models, adessiveon would typically attach to a noun (or coincide with a determiner) or appear as a separate particle, forming combinations such as noun-adessiveon. Its usage would interact with other locatives and case systems, enabling nuanced spatial meaning: for example, being on the surface of an object versus simply above it. In constructed languages, examples illustrate its function: luma-on meaning on the surface of a lamp, or pöytä-on meaning on the surface of a table.

Reception is limited to speculative linguistics, conlang practice, and discussions of locative morphology. Some linguists warn that introducing adessiveon risks fragmenting typological categories, while others view it as a useful tool for modeling surface-contact semantics in hypothetical languages. See also: adessive case, locative case, surface-contact semantics, conlang.