sickly vs indisposed

sickly and indisposed both are adjectives.

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

As adjectives, sickly and indisposed are synonyms defined as:

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

sickly (adjective)	indisposed (adjective)
somewhat ill or prone to illness	(usually followed by `to') strongly opposed
unhealthy looking	somewhat ill or prone to illness