Words that should be words that aren't words, at least not in English:

plear - adj., something pleasant. Perhaps relating to fruit. Or a quality of dry-wall. Perhaps texture.

shinp - adj., sharp, but in a specifically, terrifyingly impotent way:

"Hys eyes," quoth Wernerlitz, "as shinp as broken, crackling wendigoe bones, met myne owne."

--Fieldington, Stanship Marshdown, 1506.

gunup - n., a spear used against the genitals of the wolverine in India.

gunuj - adv., syn. "very" or "well," as in "he ran well fast" or "Ida was gunuj fair... until the skin disease."

julit - n., a kind of drink to be made only inside Scotch or Persian castles, and then only in winter.

tilg - n., a kind of poisonous mint.