epigraph (n.)

1620s, "inscription on a building, statue, etc.," from Greek epigraphe "an inscription," from epigraphein "to mark the surface, just pierce; write on, inscribe; to register; inscribe one's name, endorse," from epi "on" (see epi-) + graphein "to write" (see -graphy). Sense of "motto; short, pithy sentence at the head of a book or chapter" first recorded in English 1844. Related: Epigraphic; epigraphical.