The difference between Poorly and Sick

When used as adjectives, poorly means ill, unwell, sick, whereas sick means having an urge to vomit.

Poorly is also adverb with the meaning: in a poor manner or condition.

Sick is also noun with the meaning: sick people in general as a group.

Sick is also verb with the meaning: to vomit.

check bellow for the other definitions of Poorly and Sick

Poorly as an adverb:

In a poor manner or condition; without plenty, or sufficiency, or suitable provision for comfort.

Examples:

"to live poorly"
Poorly as an adverb:

With little or no success; indifferently; with little profit or advantage.

Examples:

"to do poorly in business"
Poorly as an adverb:

Meanly; without spirit.
Poorly as an adverb:

Without skill or merit.

Examples:

"He plays tennis poorly."

Sick as an adjective:

Having an urge to vomit.
Sick as an adjective (chiefly, American):

In poor health.

Examples:

"She was sick all day with the flu."
Sick as an adjective (colloquial):

Mentally unstable, disturbed.
Sick as an adjective (colloquial):

In bad taste.

Examples:

"That's a sick joke."
Sick as an adjective:

Tired of or annoyed by something.

Examples:

"I've heard that song on the radio so many times that I'm starting to get sick of it."
Sick as an adjective (slang):

Very good, excellent, awesome, badass.

Examples:

"This tune is sick."

"Dude, this car's got a sick subwoofer!"
Sick as an adjective:

In poor condition.

Examples:

"'sick building syndrome; my car is looking pretty sick; my job prospects are pretty sick'"
Sick as an adjective (agriculture):

Failing to sustain adequate harvests of crop, usually specified.

Sick as a noun:

Sick people in general as a group.

Examples:

"We have to cure the sick."
Sick as a noun (British, colloquial):

vomit.

Examples:

"He lay there in a pool of his own sick."

Sick as a verb:

To vomit.

Examples:

"I woke up at 4 am and sicked on the floor."
Sick as a verb (obsolete, intransitive):

To fall sick; to sicken.