scilla vs sea onion

scilla and sea onion both are nouns.

Word	Noun	Adjective	Verb	Adverb
scilla	Yes	No	No	No
sea onion	Yes	No	No	No

As nouns, sea onion is a hyponym of scilla; that is, sea onion is a word with a more specific, narrower meaning than scilla:

scilla: an Old World plant of the genus Scilla having narrow basal leaves and pink or blue or white racemose flowers
sea onion: European scilla with small blue or purple flowers

Other hyponyms of scilla include Scilla verna, spring squill.

scilla (noun)	sea onion (noun)
an Old World plant of the genus Scilla having narrow basal leaves and pink or blue or white racemose flowers	European scilla with small blue or purple flowers
	having dense spikes of small white flowers and yielding a bulb with medicinal properties