is still, except in the sporting sense, regarded as savoring of slang.
back down: A colloquialism for withdraw as from an argument, a position or contest.
back out: A colloquialism for to withdraw from or refuse to carry out an agreement.
back talk: A vulgarism for any impertinent reply; as, "Don't give me any back talk." Persons of refinement say, "Don't be impertinent," or, "stop your impertinence."
bad: This word is the antithesis of good and embraces various degrees of wickedness or evil as well as those of unsatisfactoriness. Bad is a term often misapplied. One may say "a bad boy," "a bad egg," but not a "bad accident"; say rather, "a serious accident." In referring to things which are necessarily bad, or the reverse of good, select some less pleonastic adjective. An acute, a severe or gnawing pain would be preferable expressions to a bad pain.
bad egg: An undesirable expression used colloquially to designate a worthless person: not used in polite society.
bad grammar: This phrase has been condemned as false syntax by some persons unfamiliar with the different meanings of the word bad. The phrase is not only good English but is cited by the Standard Dictionary as a correct example under the word