Definition: Edible, eatable, able to be eaten, as the yam is a large esculent tuber.
[@more@]Usage: Today's word has exactly the same meaning and distribution as "edible," so why do we even need it? It even derives from the same root as "edible" (see Etymology). The reason is simple: it is a more beautiful word than either "eatable" or "edible." The noun is esculence "edibility or degree of edibility," though most dictionaries keep this fact to themselves: "Fran's sauces raise the esculence of any vegetable."
Suggested Usage: This word may be used mundanely, "The root is the esculent part of turnip while that of the pea is the seed." However, it may be used in such a way that it sounds positively delicious, "Jacques makes a most esculent pâté de foie gras for all those who do his bidding at work." Oh, yes, one other thing—today's word itself may be used freely as a noun, "I have never seen such luscious esculents on a buffet before!"
Etymology: Today's is yet another word that comes to us from Latin via French. The Latin source is "esculentus" from esca "food," the noun from edere (es-) "to eat." The root of this verb is our old friend, *ed- "eat," which pops up in many words, including "eat," German "essen," Russian "est"—all meaning "eat." Did you know that "etch" sprang from the same seed? It came to us either through Old Dutch etsen or Old High Germanic ezzan "eat," both of which descended from *ed-. Finally, "obese" comes from Latin "obesus," the past participle of obedere "to eat away" from ob "away" + edere "eat."