Allium cepa

Many plants in the genus Allium are known by the common name onion but, used without qualifiers, it usually refers to Allium cepa. Allium cepa is also known as the 'garden onion' or 'bulb' onion and 'shallot'.
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Noun
1. bulbous plant having hollow leaves cultivated worldwide for its rounded edible bulb
(synonym) onion, onion plant
(hypernym) alliaceous plant
(hyponym) shallot, eschalot, multiplier onion, Allium cepa aggregatum, Allium ascalonicum
(substance-meronym) isothiocyanate
(part-meronym) onion