This paper aims to shed some light on the noun-verb distinction in Wayãpi, a Tupi-Guarani language spoken in Northern Brazil and French Guiana. It is often claimed that, in the languages of this family, some nouns cannot be used with a possessor and that some other ones can function as verbs, and with a quite astounding possessive reading. After presenting some definitions that enable us to better distinguish the levels of the syntactic analysis, we show that the Wayãpi data seriously call into question both these assumptions, at least how they are usually stated. This study is also an opportunity to briefly mention, within a somewhat different descriptive framework, some of the most interesting grammatical features of this still largely unknown Amazonian language (TAM clitics, serial verbs, converbs, focal position, hierarchical indexing system, periphrastic verb forms, coverbs).