Crack, n. 1. A partial separation of parts, with or without a perceptible opening; a chink or fissure; a narrow breach; a crevice; as, a crack in timber, or in a wall, or in glass.

2. Rupture; flaw; breach, in a moral sense.

My love to thee is sound, sans crack or flaw.

3. A sharp, sudden sound or report; the sound of anything suddenly burst or broken; as, the crack of a falling house; the crack of thunder; the crack of a whip.

Will the stretch out to the crack of doom?

4. The tone of voice when changed at puberty.

Though now our voices
Have got the mannish crack.

5. Mental flaw; a touch of craziness; partial insanity; as, he has a crack.

6. A crazy or crack-brained person. [Obs.]

I . . . can not get the Parliament to listen to me, who look upon me as a crack and a projector.

7. A boast; boasting. [Obs.] "Crack and brags." Burton. "Vainglorius cracks." Spenser.

8. Breach of chastity. [Obs.] Shak.

9. A boy, generally a pert, lively boy. [Obs.]

Val. 'T is a noble child. Vir. A crack, madam.

10. A brief time; an instant; as, to be with one in a crack. [Eng. & Scot. Colloq.]

11. Free conversation; friendly chat. [Scot.]

What is crack in English? . . . A crack is . . . a chat with a good, kindly human heart in it.
P. P. Alexander.

Crack, a. Of superior excellence; having qualities to be boasted of. [Colloq.]

One of our crack speakers in the Commons.

Crack, v. i. 1. To burst or open in chinks; to break, with or without quite separating into parts.

By misfortune it cracked in the coling.

The mirror cracked from side to side.

2. To be ruined or impaired; to fail. [Collog.]

The credit . . . of exchequers cracks, when little comes in and much goes out.

3. To utter a loud or sharp, sudden sound.

As thunder when the clouds in autumn crack.

4. To utter vain, pompous words; to brag; to boast; -- with of. [Archaic.]

Ethoipes of their sweet complexion crack.

Crack (krăk), v. t. [imp. & p. p. Cracked (krăkt); 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.]

1. To break or burst, with or without entire separation of the parts; as, to crack glass; to crack nuts.

2. To rend with grief or pain; to affect deeply with sorrow; hence, to disorder; to distract; to craze.

O, madam, my old heart is cracked.

He thought none poets till their brains were cracked.

3. To cause to sound suddenly and sharply; to snap; as, to crack a whip.

4. To utter smartly and sententiously; as, to crack a joke. B. Jonson.

5. To cry up; to extol; -- followed by up. [Low]

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.]