sickly vs poorly

sickly and poorly both are adjectives.

Word	Noun	Adjective	Verb	Adverb
sickly	No	Yes	No	No
poorly	No	Yes	No	Yes

As adjectives, sickly and poorly are synonyms defined as:

Other synonyms of sickly include ailing, indisposed, peaked, seedy, under the weather, unwell.

sickly (adjective)	poorly (adjective)
somewhat ill or prone to illness	somewhat ill or prone to illness
unhealthy looking

sickly (adverb)	poorly (adverb)
	(`ill' is often used as a combining form) in a poor or improper or unsatisfactory manner; not well