apostrophe

noun

1. The text character ’, which serves as a punctuation mark in various languages and as a diacritical mark in certain rare contexts.

   “Since its inception the apostrophe has been a controversial piece of punctuation.”

2. (countable, rhetoric, uncountable)A sudden exclamatory piece of dialogue addressed to someone or something, especially absent.

   “Apostrophe a bold digression makes, Mov'd by some sudden thought the theme awakes.”

   “The warm apostrophe of Riccardini to this little representative of his parents, whom he called "the son of his love, the child of his old age, the gift of his beloved niece, on the behalf of his angel-daughter," affected them all;...”

3. An arrangement of chlorophyll grains perpendicular to the outer surface of plant cells, as opposed to epistrophe (an arrangement on the outer surface).

   “As is well known, chloroplast in the epistrophe position presents an oval or more or less circular form; in the apostrophe position a flattened and lenticular form.”