Final answer:
A pun is a form of humor that plays on the multiple meanings of a word or phrases that sound similar but have different meanings. It is correctly defined as 'a joke using words that sound alike but have different meanings'. Puns are different from satire or the playful use of synonyms.
Step-by-step explanation:
A pun is a joke exploiting the different possible meanings of a word or the fact that there are words that sound alike but have different meanings. The correct description of a pun from the options given is 'a joke using words that sound alike but have different meanings'. For instance, the statement 'Time flies like an arrow; fruit flies like a banana' plays on the word 'flies' to be both a verb related to time moving quickly and a noun referring to the insect that is attracted to fruit.
Another example of a pun would be: 'I used to be a baker, but I couldn't make enough dough'. Here, 'dough' refers to both the bread mixture and slang for money. This form of wordplay can also be found in literature, where puns are often utilized by authors to inject humor and convey dual meanings.
Puns are different from satire, which is a broader literary device that uses humor, exaggeration, or ridicule to criticize or expose flaws in human behavior or institutions. Additionally, a pun is not simply the use of synonyms, nor is it exactly the quatrain in poetry or merely the punchline of a joke.