From Peter Selgin:
The novelist Martin Amis calls all writing a "campaign against cliché." "Not just clichés of the pen," he writes,"but clichés of the mind and clichés of the heart."
A cliché is a figure of speech that once had its moment in the sun. Once upon a time, the phrase It's raining cats and dogs was poetry worthy of Shakespeare. Now it's just a poor little tired old cliché. Were you the first to coin that expression, you'd be rightly proud. But you're not, . . . .
Most clichés are fairly prosaic: desperately lonely qualifies; so does wreaked havoc; so does abject poverty (what other kind is there?) and sweating profusely and every name in the book. Said too often, even "the heaventree of stars hung with humid nightblue fruit," Joyce's most gorgeous line in Ulysses, risks turning into a cliché.