Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† caerĕfŏlĭum, ii (chaerĕphyl-lum, Col. 10, 110), n. [χαιρέφυλλον, whence the Fr. cerfeuil, and Germ. Kerbel], chervil, Plin. 19, 8, 54, § 170; Pall. Febr. 24, 9; id. Sept. 13, 3; App. Herb. 104.