(See also THWARTING.)

cut the ground from under To disprove or invalidate someone’s argument, case, position, etc., by demonstrating that it has no foundation in fact; to devastate someone by destroying his belief in an idea or his faith in a person. In this expression, ground is what supports a person or his perceptions, whatever sustains him or informs his life.

flub the dub To ruin one’s own chances of success by inept or evasive behavior; to think or act awkwardly, inefficiently, or slowly; to be slothful and indolent; to blunder or bungle. This expression enjoyed limited popularity during World War II, but flub has remained in fairly widespread contemporary use. Related expressions are flubdub ‘pompous bombastic language inappropriate to a situation’ and flubadub ‘awkwardness, ineptitude.’ It is interesting to note that Flubadub was the name of the awkward, bumbling, nondescript circus animal (puppet) in the original Howdy Doody Show (1947-60).

gum up the works To botch or mess things up, to screw things up; to spoil or ruin, to interfere with the smooth operation of things; also to gum or gum up and to gum the game. The allusion is to the clogging effect gum or a gummy substance has on machinery. The figurative use of this American slang expression dates from at least 1901.

knock for six To demolish an argument or defeat an opponent utterly and completely; to knock for a loop or into a cocked hat. This primarily British expression derives from cricket; a batsman knocks for six when he knocks the ball over the boundary of the field and scores six runs. The feat is similar to hitting a homerun in baseball, a game more familiar to Americans.

knock into a cocked hat To demolish or defeat utterly; to destroy, upset, or ruin. Though it may refer to actual physical combat, the expression is more often used in reference to plans, arguments, theories, etc. Most sources agree it derives from a game similar to ninepins, popular in the United States in the 19th century. When only the three pins forming a triangle were left standing, they were said to have been “knocked into a cocked hat”—by analogy with the shape of the tricornered, brimmed hat worn during the American Revolution.

make mincemeat of To destroy or annihilate; to beat in a contest. This expression, dating from the 17th century, can be used in referring to actual physical destruction or to the destruction of a person’s ideas or theories.

The use referring to beating an opponent in a contest seems to be a later development, appearing in print by the mid-19th century.

An equivalent slang expression is make hamburger out of, an Americanism which applies almost exclusively to severe physical beating or thrashing.

pull the rug out from under To cut the ground from under someone; to suddenly and effectively shatter another’s position, argument, or belief by demonstrating its invalidity; to deflate someone by destroying his illusions.

upset the applecart To ruin plans or arrangements, to botch things up, to spoil things, to blight someone’s hopes. An applecart is a pushcart street vendors use to peddle apples. For a huckster who makes his living selling apples, the overturning of his cart would be disastrous since it would inevitably damage the fruit and thus ruin his business. A variant of the expression dates from at least 1788.