OXFORD DICTIONARY
onion, n.
1 a liliaceous plant, Allium cepa, having a short stem and bearing greenish-white flowers.
2 the swollen bulb of this with many concentric skins used in cooking, pickling, etc.
know one's onions be fully knowledgeable or experienced. onion dome a bulbous dome on a church, palace, etc. onion-skin
1 the brown outermost skin or any outer skin of an onion.
2 thin smooth translucent paper.
oniony adj.
ME f. AF union, OF oignon ult. f. L unio -onis
ROGET THESAURUS
onion
Condiment
N
condiment, seasoning, sauce, spice, relish, appetizer, salt, mustard, grey poupon mustard, pepper, black pepper, white pepper, peppercorn, curry, sauce piquante, caviare,
onion, garlic, pickle, achar, allspice, bell pepper, Jamaica pepper, green pepper, chutney, cubeb, pimento, capsicum, red pepper, chili peppers, cayenne, nutmeg, mace, cinnamon, oregano, cloves, fennel, pot herbs, parsley, sage, rosemary, thyme, bay leaves, marjoram, frankincense, balm, myrrh, paprika, saffron, ginger, turmeric.