It was common enough in Classical Latin.

Indeed, Latin grammar distinguished between two kinds of nomina 'names; nouns': nomina substantiva (what we call nouns) 'nouns substantive' and nomina adjectiva 'nouns adjective' (what we call adjectives). This was based on the similar morphology of both those grammatical classes. Besides that, two nouns in apposition seems a lot like a nominal compound to me.

Ceci n'est pas un seing.