Sickly means so sweet or rich that it turns the stomach. A sickly smell, sickly sweet, sickly rich.
Sickly sweet is the fixed phrase and it is always a complaint. The other main sense describes a person who is often ill — a sickly child — which is dated and slightly Victorian. Applied to a colour it means pale and unpleasant: a sickly green. Note sickliness; and that sickly means causing sickness in one sense and suffering it in the other.
1adjectivesicklySo sweet or rich that it turns the stomach.
“The perfume had a sickly smell, like flowers left too long in a vase.”
2adjectiveillOften ill.
“She was a sickly child who missed a lot of school.”
sickly is a quality of cloying or illness.
Middle English sekely is sick plus -ly, possibly reinforced by Old Norse sjukligr. It is one of the -ly words that is an adjective rather than an adverb.
Old Norse
sjúkligr — sickly
Old English
sīcle — sickly
Middle English
seekly
English, today
sickly
From Middle English seekly, sekely, siklich, sekeliche, equivalent to sick + ly. Possibly a modification of Old English sīcle (“sickly”) and/or derived from Old Norse sjúkligr (“sickly”). Cognate with Dutch ziekelijk, Middle High German siechlich, Danish sygelig, Swedish sjuklig, Icelandic sjúklegur. The verb is from the adjective.
Etymology from Wiktionary, CC BY-SA
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