Final answer:
An apostrophe is a punctuation mark used to indicate possession or the omission of letters in contractions. It is also a term used to describe a figure of speech where the speaker addresses an absent or unidentified person or speaks to the reader as if they are the protagonist.
Step-by-step explanation:
The term 'apostrophe' has multiple meanings. In terms of punctuation, an apostrophe is used to indicate possession or the omission of letters in contractions. For example, 'Jack's brother' shows possession and 'don't' is a contraction that omits the letter 'o' from 'do not'. Additionally, 'apostrophe' is also a term used to describe a figure of speech where the speaker addresses an absent or unidentified person or speaks to the reader as if they are the protagonist. For instance, 'O Death, where is thy sting?'