These words are much less commonly used than once they were, but the phrase "warp and woof" is often heard in the meaning of ''the underlying structure upon which something is built," "the foundation or base": "The Constitution is the warp and woof of our system of government." Literally, warp refers to the threads that run lengthwise in fabric, crossed at right angles by the woof, the threads that run crosswise: "The warp and woof of this piece of cloth provide a clear impression of its texture."
Dictionary of problem words and expressions. Harry Shaw. 1975.