Definition of "superscription"

Hovv counterfeit a coin they are vvho friends / Bear in their Superſcription (of the moſt / I vvould be underſtood) in proſperous days / They ſvvarm, but in adverſe vvithdravv their head / Not to be found, though ſought.

1671, John Milton, “Samson Agonistes, […]”, in Paradise Regain’d. A Poem. In IV Books. To which is Added, Samson Agonistes, London: […] J. M[acock] for John Starkey […], page 19, lines 190–194

"Dear me, Mr. Holmes. Dear me!" said this singular epistle. There was neither superscription nor signature. I laughed at the quaint message; but Holmes showed unwonted seriousness.

1914 September – 1915 May, Arthur Conan Doyle, The Valley of Fear: A Sherlock Holmes Novel, New York, N.Y.: George H[enry] Doran Company, published 27 February 1915

Its superscription was my name, and the name of the sender, my mother.

1930, Pearl S. Buck, East Wind: West Wind, Moyer Bell, page 124

Schwartz glanced at the printed superscription on the envelope and grumbled as he put the envelope away in his overcoat pocket, to read at leisure.

1983, Lawrence Durrell, Sebastian (Avignon Quintet), Faber & Faber, published 2004, page 1140

By a pure error, or perhaps through a confusion in the traditions, Achish the Philistine (of Gath, 1 Sam. xxi., xxvii.), to whom David fled, is called Abimelech in the superscription to Psalm 34.

1911, Encyclopædia Britannica