If you're ill, you're unwell, or sick. Being ill is a good excuse for missing work or school.

You might get ill after being sneezed on by someone with a cold; or eating street food in a foreign country; or for no reason that you can point to. People can be mentally ill as well as physically ill, from depression or anxiety among other ailments. Ill can also mean "bad" in various ways, including when you suffer ill effects from going too long without sleep, or exercise ill judgment when you buy $500 worth of lottery tickets.

Definitions of ill
  1. adjective
    affected by an impairment of normal physical or mental function
    ill from the monotony of his suffering”
    synonyms: sick
    not in good physical or mental condition; out of condition
    not in or exhibiting good health in body or mind
    afflicted, stricken
    grievously affected especially by disease
    affected by ague
    ailing, indisposed, peaked, poorly, seedy, sickly, under the weather, unwell
    somewhat ill or prone to illness
    air sick, airsick, carsick, seasick
    experiencing motion sickness
    characteristic of or affected with autism
    bedfast, bedrid, bedridden, sick-abed
    confined to bed (by illness)
    bilious, liverish, livery
    suffering from or suggesting a liver disorder or gastric distress
    suffering from or prone to bronchitis
    afflicted with or associated with pulmonary tuberculosis
    convalescent, recovering
    returning to health after illness or debility
    delirious, hallucinating
    experiencing delirium
    suffering from diabetes
    dizzy, giddy, vertiginous, woozy
    having or causing a whirling sensation; liable to falling
    suffering from dyspepsia
    faint, light, light-headed, lightheaded, swooning
    weak and likely to lose consciousness
    feverish, feverous
    having or affected by a fever
    experiencing odd bodily sensations
    suffering from gout
    looking pale and unhealthy
    laid low, stricken
    put out of action (by illness)
    laid up
    ill and usually confined
    affected with or related to milk sickness
    nauseated, nauseous, queasy, sick, sickish
    feeling nausea; feeling about to vomit
    affected with palsy or uncontrollable tremor
    paralytic, paralyzed
    affected with paralysis
    suffering complete paralysis of the lower half of the body usually resulting from damage to the spinal cord
    rachitic, rickety
    affected with, suffering from, or characteristic of rickets
    afflicted with scrofula
    inclined to sneeze
    suffering from spastic paralysis
    tubercular, tuberculous
    constituting or afflicted with or caused by tuberculosis or the tubercle bacillus
    not healed
    mildly physically distressed
    see moresee less
    in good health especially after having suffered illness or injury
    physically and mentally sound or healthy
    having or indicating good health in body or mind; free from infirmity or disease
    asymptomatic, symptomless
    having no symptoms of illness or disease
    cured, healed, recovered
    freed from illness or injury
    show more antonyms...
  2. adjective
    resulting in suffering or adversity
    ill effects”
    “it's an ill wind that blows no good”
    causing or capable of causing harm
  3. adjective
    ill manners”
    “of ill repute”
    having undesirable or negative qualities
  4. adjective
    presaging ill fortune
    ill omens”
    ill predictions”
    synonyms: inauspicious, ominous
    not propitious
  5. adverb
    (`ill' is often used as a combining form) in a poor or improper or unsatisfactory manner; not well
    “he was ill prepared”
    “it ill befits a man to betray old friends”
    ill-fitting clothes”
    “an ill-conceived plan”
    synonyms: badly, poorly
    see moresee less
    good, well
    (often used as a combining form) in a good or proper or satisfactory manner or to a high standard (`good' is a nonstandard dialectal variant for `well')
  6. adverb
    with difficulty or inconvenience; scarcely or hardly
    “we can ill afford to buy a new car just now”
  7. noun
    an often persistent bodily disorder or disease; a cause for complaining
    synonyms: ailment, complaint
    see moresee less
    show 5 types...
    hide 5 types...
    a minor nonspecific ailment
    kinetosis, motion sickness
    the state of being dizzy or nauseated because of the motions that occur while traveling in or on a moving vehicle
    air sickness, airsickness
    motion sickness experienced while traveling by air (especially during turbulence)
    car sickness
    motion sickness experienced while traveling in a car
    mal de mer, naupathia, seasickness
    motion sickness experienced while traveling on water
    type of:
    disorder, upset
    a physical condition in which there is a disturbance of normal functioning
  8. adjective
    indicating hostility or enmity
    “you certainly did me an ill turn”
    ill feelings”
    ill will”
    characterized by enmity or ill will
  9. adverb
    unfavorably or with disapproval
    “tried not to speak ill of the dead”
    synonyms: badly
    see moresee less
    favorably; with approval
Word Family