1.  sustenance(n = noun.food) aliment, alimentation, nourishment, nutriment, nutrition, victuals - a source of materials to nourish the body;
Derived form verb sustain₃

2.  sustenance(n = noun.possession) bread and butter, keep, livelihood, living, support - the financial means whereby one lives; "each child was expected to pay for their keep"; "he applied to the state for support"; "he could no longer earn his own livelihood"
Derived form verb sustain₄

3.  sustenance(n = noun.act) maintenance, sustainment, sustentation, upkeep - the act of sustaining life by food or providing a means of subsistence; "fishing was their main sustainment"; "they were in want of sustenance"
Derived form verb sustain₁

1.  The act of sustaining; support; maintenance; subsistence; as, the sustenance of the body; the sustenance of life. [1913 Webster]

2.  That which supports life; food; victuals; provisions; means of living; as, the city has ample sustenance. Chaucer. [1913 Webster]

sustenance, n.
1 a nourishment, food. b the process of nourishing.
2 a means of support; a livelihood.

Etymology:
ME f. AF sustenaunce, OF so(u)stenance (as SUSTAIN)

N  food, eating, deglutition, gulp, epulation, mastication, manducation, rumination, gluttony, hippophagy, ichthyophagy, (appetite), mouth, jaws, mandible, mazard, gob, chops, drinking, potation, draught, libation, carousal, drunkenness, food, pabulum, aliment, nourishment, nutriment, sustenance, sustentation, sustention, nurture, subsistence, provender, corn, feed, fodder, provision, ration, keep, commons, board, commissariat, prey, forage, pasture, pasturage, fare, cheer, diet, dietary, regimen, belly timber, staff of life, bread, bread and cheese, comestibles, eatables, victuals, edibles, ingesta, grub, grubstake, prog, meat, bread, bread stuffs, cerealia, cereals, viands, cates, delicacy, dainty, creature comforts, contents of the larder, fleshpots, festal board, ambrosia, good cheer, good living, beef, bisquit, bun, cornstarch, cookie, cooky, cracker, doughnut, fatling, hardtack, hoecake, hominy, mutton, pilot bread, pork, roti, rusk, ship biscuit, veal, joint, piece de resistance, roast and boiled, remove, entremet, releve, hash, rechauffe, stew, ragout, fricassee, mince, pottage, potage, broth, soup, consomme, puree, spoonmeat, pie, pasty, volauvent, pudding, omelet, pastry, sweets, kickshaws, condiment, appetizer, hors d'oeuvre, main course, entree, alligator pear, apple, apple slump, artichoke, ashcake, griddlecake, pancake, flapjack, atole, avocado, banana, beche de mer, barbecue, beefsteak, beet root, blackberry, blancmange, bloater, bouilli, bouillon, breadfruit, chop suey, chowder, chupatty, clam, compote, damper, fish, frumenty, grapes, hasty pudding, ice cream, lettuce, mango, mangosteen, mince pie, oatmeal, oyster, pineapple, porridge, porterhouse steak, salmis, sauerkraut, sea slug, sturgeon ("Albany beef"), succotash, supawn, trepang, vanilla, waffle, walnut, table, cuisine, bill of fare, menu, table d'hote, ordinary, entree, meal, repast, feed, spread, mess, dish, plate, course, regale, regalement, refreshment, entertainment, refection, collation, picnic, feast, banquet, junket, breakfast, lunch, luncheon, dejeuner, bever, tiffin, dinner, supper, snack, junk food, fast food, whet, bait, dessert, potluck, table d'hote, dejeuner a la fourchette, hearty meal, square meal, substantial meal, full meal, blowout, light refreshment, bara, chotahazri, bara khana, mouthful, bolus, gobbet, morsel, sop, sippet, drink, beverage, liquor, broth, soup, potion, dram, draught, drench, swill, nip, sip, sup, gulp, wine, spirits, liqueur, beer, ale, malt liquor, Sir John Barleycorn, stingo, heavy wet, grog, toddy, flip, purl, punch, negus, cup, bishop, wassail, gin, coffee, chocolate, cocoa, tea, the cup that cheers but not inebriates, bock beer, lager beer, Pilsener beer, schenck beer, Brazil tea, cider, claret, ice water, mate, mint julep, near beer, 2 beer, non- alcoholic beverage, eating house, diner, hippophage, glutton, eatable, edible, esculent, comestible, alimentary, cereal, cibarious, dietetic, culinary, nutritive, nutritious, gastric, succulent, potable, potulent, bibulous, omnivorous, carnivorous, herbivorous, granivorous, graminivorous, phytivorous, ichthyivorous, omophagic, omophagous, pantophagous, phytophagous, xylophagous, across the walnuts and the wine, blessed hour of our dinners!, now good digestion wait on appetite, and health on both!, who can cloy the hungry edge of appetite?.