sick

\ ˈsik \  

adjective

1. afflicted with ill health or disease; ailing. affected with nausea; inclined to vomit.
2. deeply affected with some unpleasant feeling, as of sorrow, disgust, or boredom.
3. mentally, morally, or emotionally deranged, corrupt, or unsound.
4. dwelling on or obsessed with that which is gruesome, sadistic,ghoulish, or the like; morbid.
5. very annoyed or bored by something because you have had too much of it.
6. Slang. great; amazing

verb

1. to attack (used especially in commanding a dog)
2. to incite to attack (usually followed by on).

Synonyms:
ailing, bad, down, ill, indisposed, peaked, peaky, poorly, punk, run-down, sickened, unhealthy, unsound, unwell, out of sorts, under the weather

Antonyms:
hale, healthful, healthy, sound, well, whole, wholesome

Prefix: be-, un-

Suffix: -ness, -ly, -er, nesses, -est, -ish, -ening, -ened, -en, -eningly, -liness

Derived:
seasick, sickroom, airsick, sickhouse, love-sick, sicko, homesick,  heartsick,  musicking, sickbed, fossicking, physicking, sickbag, physicked,  carsick

Origin and Etymology:
before 900;

Middle English sik, sek, Old English sēoc; cognate with Dutch ziek, German siech, Old Norse sjūkr, Gothic siuks