Noun-clad adjectives. On the adjectival status of non head constituents of Italian attributive compounds

In Italian appositive compounds like parola chiave ("key word"), the non-head constituent (N2) often undergoes a metaphorical interpretation and behaves like an adjective, emphasising a property of the head (N1). The research question of the work described in this paper is: Are these really noun-clad adjectives? Specifically: (1) Do N2s formally show a morpho-syntactic behaviour typical of adjectives? (2) Do N2s semantically show a selection of features that are normally associated with real adjectives modifying N1 (e.g. riunione lunga and riunione fiume)? We have designed a few corpus-based studies to address these questions, and we observed that (1) formally, N2s do share some of the typical properties of adjectives, but not all, thus implying gradience in the definition of part-of-speech classes; (2) semantically N2 do behave like adjectives and the implied sense of N2 can be obtained via objective criteria, exploiting corpus data.