Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
* formācĕus, a, um, adj. [forma], made in a form or mould: parietes, quos appellant formaceos, quoniam in forma circumdatis duabus utrimque tabulis inferciuntur verius quam instruuntur, Plin. 35, 14, 48, § 169.