noun an often persistent bodily disorder or disease; a cause for complaining
adjective affected by an impairment of normal physical or mental function
Synonymssick
Similarafflictedaguishailingairsickautisticbedfastbiliousbronchiticconsumptiveconvalescentdeliriousdiabeticdizzydyspepticfaintfeverishfunnygoutygreenlaid lowlaid upmilk-sicknauseatedpalsiedparalyticparaplegicricketyscrofuloussneezyspastictubercularunhealedupset
Oppositeswell
adjective resulting in suffering or adversity
Similarharmful
adjective distressing
Similarbad
adjective indicating hostility or enmity
Similarhostile
adverb (`ill' is often used as a combining form) in a poor or improper or unsatisfactory manner; not well
Oppositeswell
Source: WordNet 3.1, Princeton University