Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
signĭfex, fĭcis, m. [signum-facio], an image-maker, carver, statuary (post-class.), App. M. 2, p. 116, 13; Arn. 6, 199; Mart. Cap. 1, § 36; Sid. Ep. 6, 12.