lady: The use of this word as "a mere distinction of sex is a sheer vulgarism." Never say "A man and his lady," but "a man and his wife," or preferably, by name, "Mr. and Mrs. John Smith." Where woman, as indicative of sex, is intended, say woman—not lady or female. A female is equally female, whether person or beast. In the United States "woman" is preferable; in England "lady" is used chiefly when the term is not preceded by a qualifying adjective. The word woman best expresses the relation of the female sex to the human race. Some ill-informed persons use lady for woman under the mistaken idea that woman is a derogatory term; such use is downright vulgarity. As one never hears salesgentleman but salesman, therefore saleslady should be avoided; say, rather, saleswoman.
lambaste is slang and as such should not be used as a substitute for "flog," "whip," or ["]beat."
lassitudinous is not a desirable substitute for "languid" or "weary."
last, latter: The first of these words is not properly used of only two, since it is a superlative; the second, not properly of more than two, since it is a comparative. Notwithstanding the fact that the use of last for latter and of latter for last has had wide sanction, the present tendency is toward strict construction.