mark indicating omitted letter, 1580s, from Middle French apostrophe, from Late Latin apostrophus, from Greek apostrophos (prosoidia) "(the accent of) turning away," thus, a mark showing where a letter has been omitted, from apostrephein "avert, turn away," from apo- "from" (see apo-) + strephein "to turn" (see strophe).
In English, the mark often represents loss of -e- in -es, possessive ending. It was being extended to all possessives, whether they ever had an -e- or not, by 18c. Greek also used this word for a "turning aside" of an orator in speech to address some individual, a sense first recorded in English 1530s.
A mark (') used with a noun or pronoun to indicate possession (“the student's comment,” “the people's choice”) or in a contraction to show where letters have been left out (isn't, don't, we'll).
a rhetorical device by which a speaker turns from the audience as a whole to address a single person or thing. For example, in William Shakespeare's Julius Caesar, Mark Antony addresses the corpse of Caesar in the speech that begins:O, pardon me, thou bleeding piece of earth,That I am meek and gentle with these butchers!Thou art the ruins of the noblest manThat ever lived in the tide of times.Woe to the hand that shed this costly blood