the GNU version of the Collaborative International Dictionary of English
adj. Of or pertaining to the rictus.
The Century Dictionary and Cyclopedia
In ornithology, of or pertaining to the rictus: as, rictal vibrissæ. See rictus
Word Usage
"The engraver's tools make beautiful striations and cross-hatchings on foliage and on birds' wings and rictal bristles, feathers fine as whiskers, that watercolor alone can never produce."