This paper presents a lexical and syntactic study of the polysemy of the noun truc ‘thing’ in French, which displays (at least) five different types of uses, some of which bring it close to unspecific and/or general nouns. The analysis is based on a large corpus of attested data and on a set of syntactic patterns allowing us to both distinguish and characterize the relevant uses of the noun truc. It is shown that each type of use of truc as an unspecific noun can be characterized by preferably selecting one favored syntactic pattern, while allowing one or more others. More precisely, it turns out that each of the five meanings of the noun truc can be defined by virtue of a conjunction of several discriminant syntactic and semantic features.