From The Collaborative International Dictionary of English v.0.48:
Crack \Crack\ (kr[a^]k), v. t. [imp. & p. p. Cracked
(kr[a^]kt); p. pr. & vb. n. Cracking.] [OE. cracken,
craken, to crack, break, boast, AS. cracian, cearcian, to
crack; akin to D. kraken, G. krachen; cf. Skr. garj to
rattle, or perh. of imitative origin. Cf. Crake,
Cracknel, Creak.]
[1913 Webster]
1. To break or burst, with or without entire separation of
the parts; as, to crack glass; to crack nuts.
[1913 Webster]
2. To rend with grief or pain; to affect deeply with sorrow;
hence, to disorder; to distract; to craze.
[1913 Webster]
O, madam, my old heart is cracked. --Shak.
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He thought none poets till their brains were
cracked. --Roscommon.
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3. To cause to sound suddenly and sharply; to snap; as, to
crack a whip.
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4. To utter smartly and sententiously; as, to crack a joke.
--B. Jonson.
[1913 Webster]
5. To cry up; to extol; -- followed by up. [Low]
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To crack a bottle, to open the bottle and drink its
contents.
To crack a crib, to commit burglary. [Slang]
To crack on, to put on; as, to crack on more sail, or more
steam. [Colloq.]
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
cracking \cracking\ n.
1. the act of cracking something.
Syn: fracture, crack.
[WordNet 1.5]
2. (Chem.) the process of making lower molecular weight
hydrocarbons from heavier hydrocarbons in petroleum, by
exposure to heat and catalysts. It is used to convert
heavier alkanes into gasoline, or to improve the octane
number of an alkane mixture.
[PJC]
From The Collaborative International Dictionary of English v.0.48:
cracking \cracking\ adj.
same as groovy, sense 1. [informal]
Syn: bang-up, bully, cool, corking, dandy, great, groovy,
keen, neat, nifty, not bad(predicate), peachy, slap-up,
swell, smashing.
[WordNet 1.5]