Definition
To crack is to undergo partial breaking.
Etymology. O.E. cracian "make a sharp noise," from P.Gmc. *krakojan, probably onomatopoeic. The noun meaning "split, opening," is 14c. Meaning "try, attempt" first attested 1836, probably a hunting metaphor, from slang sense of "fire a gun." Meaning "rock cocaine" is first attested 1985. Cracked "mentally unsound" is 17c. (though the equivalent Gk. word was used in this sense by Aristophanes), while crack as in "top-notch, superior" is slang from 1793. Crackpot "pretentious, worthless person" dates from 1883. The superstition that it is bad luck to step on sidewalk cracks has been traced to c.1890.