crack: [OE] Old English had the verb cracian ‘make a sudden sharp noise’, but English did not acquire the noun crack until the 14th century. Both are of Germanic origin (modern German has the related krachen, for instance, and Dutch has kraken), and the verb’s hypothetical ancestor can be reconstructed as *krakojan. The notion of ‘sudden sharp noise’ is semantically primary (presumably it was originally onomatopoeic), and the prevalent modern sense ‘fissure’ arises from the connection between the noise of something breaking and the resultant line of fracture. => crock
