Especially in engineering, a crock is a botched attempt or design to achieve something. An automobile with intentionally designed square wheels would be a crock. (Crock itself is a slang word meaning something which is broken down or worn out or which is nonsense.)
Most of Rube Goldberg's or Heath Robinson's unlikely machines were crocks. Because they were crocks, they were funny. In absolute contrast, there is little more condemnatory in an engineering context than to declare something a crock.
A kludge, by contrast is typically something that works, however clumsily. A kludged design which didn't actually work, will probably also be a crock.
The term was early used at the MIT Model Railroad Club, and from there moved to computing and into computing terminology.
According to the Jargon File, the use of the word "crock" as engineering jargon is connected to its use for dishware by the American scatologism crock of shit for extreme forms of what would otherwise be called bullshit.
In sport, especially football, the word crocked can also be used as a synonym for injured, thus describing a sportsperson who is hurt and unable to compete.