early 13c., poureliche, "inadequately, badly, insufficiently," from poor (adj.) + -ly (2). Modern form from 15c. Meaning "in poverty" is from mid-14c. Meaning "indisposed, in somewhat ill health" is from 1750.
the team played poorly
feeling poorly
poop
pooped
poor
poor-box
poorhouse
poorly
poorness
poor-rate
pop
popcorn
pope