Same entry, according to Adler, in the Ambrosian Lexicon (1333). The headword prometwpi/dion is either the neuter nominative/accusative singular of the adjective prometwpi/dios (and thus quoted from somewhere) or else the neuter substantive, prometwpi/dion, skin of the forehead or a frontlet, especially for horses; cf. phi 56 (gloss) and generally LSJ s.v.
[1] See also pi 2553 (gloss) and generally LSJ s.v. e)/mprosqen, an adverb often used as a preposition (Smyth §1700, web address 1).