Runcible is a nonsense word invented by Edward Lear. He appears to have been very pleased with the word, and it appears in several of his works, describing various objects. The Owl and the Pussycat eat “with a runcible spoon." So does the Dolomphious Duck, in alphabetical illustrations, Twenty-Six Nonsense Rhymes and Pictures.
In The Self-Portrait of the Laureate of Nonsense, Lear states that "he weareth a runcible hat." In other poems he refers to a "runcible cat," a "runcible goose" (referring to a silly person), and a "runcible wall.”
Lear appears to have favoured the word for its sound, rather than for any imagined meaning. Since the 1920s, however, dictionaries have determined that a "runcible spoon" is a fork with three broad curved prongs and a sharpened edge, used for pickles or hors d’oeuvres. Lear's own drawing of said spoon, however, looks more like a ladle. And there is of course the cat, the goose, and wall….