Chronic

adj. lingering, lasting (as of an illness); constant

Chronic may refer to: Chronic (medicine), a persistent and lasting disease or medical condition, or one that has developed slowlyA specific strain of cannabis Cannabis (drug)The Chronic, a 1992 album by Dr. Dre2001 (album), a 1999 album by Dr. Dre originally to be called The Chronic 2001A reference to Lazy SundaySlang for bad, extremely unpleasant
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Adjective
1. being long-lasting and recurrent or characterized by long suffering; "chronic indigestion"; "a chronic shortage of funds"; "a chronic invalid"
(antonym) acute
(similar) degenerative
(classification) medicine, medical specialty
2. having a habit of long standing; "a chronic smoker"
(synonym) confirmed, habitual, inveterate(a)
(similar) addicted

(a.)
Relating to time; according to time.
  

(a.)
Continuing for a long time; lingering; habitual.
  

This is an important term in medicine. It comes from the Greek chronos meaning time (as in chronometer). It means lasting a long time. A chronic condition is one lasting 3 months or more, by the definition of the U.S. National Center for Health Statistics. In ancient Greece, the "father of medicine" Hippocrates distinguished diseases that were acute (abrupt, sharp and brief) from those that were chronic. This is still a very useful distinction. Subacute has been coined to designate the mid-ground between acute and chronic.