From Longman Dictionary of Contemporary Englishonionon‧ion /ˈʌnjən/ ●●● S3 noun [countable, uncountable] 
DFa round white vegetable with a brown, red, or white skin and many layers. Onions have a strong taste and smell Chop the onions finely. red onions home-made onion soup
DFa round white vegetable with a brown, red, or white skin and many layers. Onions have a strong taste and smell Chop the onions finely. red onions home-made onion soupExamples from the Corpus
onion• At Cheltenham there are leeks to marvel at ... and onions which would make any eye water.• In a food mill or using short pulses in a food processor, puree parsnips and onion mixture.• The meat is then ready to be cooked with the sauce and any other ingredients such as onions and mushrooms.• Mix the ground beef with the cooked onions and butter.• Add remaining 2 tablespoons oil to pan and saute onion and garlic until lightly browned.• Bananas, tacos, onions, pecans surrounded him.• Dry-fry the onion and garlic for 5 minutes.• Add to the pan with the onion and garlic and a little water and cook gently.Origin onion (1100-1200) Old French oignon, from Latin unio 