The possible nominal use of the lexeme in Five Med MSS may be the result of an erroneous insertion of the de preposition, to represent Latin oleum rosaceum, possibly in parallel with a similar fluctuation between ewe rose and ewe de roses (cf. ewerose and rose¹) or oile rosé and oil de rose (cf. rosé¹ and rose¹). For a similar expression, see oil de rosat sub rosat. AND¹’s emendation of roseac to roseat in the same Five Med MSS attestation, and the subsequent creation of a separate entry, seems unnecessary.