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.
The deep crease between the buttocks (unknown date, but very old)
(also crack cocaine) Cocaine freebase, a very pure crystalline cocaine intended for smoking rather than inhalation; coke: Crack's low price and quick payoff make it especially alluring to teenagers(1985+ Narcotics)
[all senses are ultimately echoic; narcotics sense fr the sound of breaking crystals or the cracking sound the crystals make when smoked]
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with crack up
Suffer an emotional breakdown, become insane, as in He might crack up under the strain. This usage alludes to the result of cracking one's skull; from the early 1600s to crack alone was used in this way.
[ ; early 1900s
Damage or wreck a vehicle or vessel. For example, I'm always afraid that I'll crack up the car.
Experience a crash, as in We cracked up on the freeway in the middle of the ice storm.
crack someone up. Burst or cause to burst out laughing, as in The audience cracked up, or That joke really cracked me up.
[ ; c. 1940