An epigram is (1) a concise, clever saying, or (2) a short, witty poem. An epigraph is (1) a motto or quotation at the beginning of a literary composition, or (2) an inscription on a statue or building. An epigram can be an epigraph, but the two are far from interchangeable.
Of course, epigraph is not to be confused with epitaph, which is an inscription on a tombstone.
Examples
These writers use epigram correctly:
And for those pining for Karl’s Twitter wisdom, here’s his latest epigram: Luxury is the ease of a t-shirt in a very expensive dress. [Guardian]
The famous epigram attributed to Joseph Stalin says that: “The death of one man is a tragedy, the death of millions is statistics.” [Hurriyet Daily News]
It is often said that the cost of freedom is never free, and that makes a nice bumper-sticker epigram. [Hi-Desert Star]
And these writers use epigraph well:
Hajnoczky sets the tone for her with a (somewhat condensed) epigraph from Aldous Huxley … [Winnipeg Free Press]
In fact, let Steinbeck have the last word, since Williams graces one of her chapters with an epigraph from him … [Los Angeles Times]
Their yearning is summed up in the novel’s epigraph from Walter Benjamin: “The word must communicate something (other than itself).” [The Millions]
