Homonyms are words which have the same form, but different meanings. Words which have the same spelling but different meanings are called homographs, such as bow (v.) and bow (n., a weapon). Words which have the same pronunciation but different meanings are called homophones. Flour/flower, pale/pail, whole/hole are all homophones. Words which have the same spelling and pronunciation but different meanings are full homonyms, as exemplified by bear (v.)/bear (an animal), ground (n.)/ground(v.).

　 Rhetorically, homonyms are often used as puns. In Lewis Carroll's famous novel Alice's Adventures in Wonderland, some humorous dialogs are found:

“Mine is a long and sad tale!” said the Mouse, turning to Alice and sighing. “It is a long tail, certainly,” said Alice, looking with wonder at the mouse's tail, “but why do you call it sad?”

“How is bread made?”
“I know that!” Alice cried eagerly.
“you take some flour ---”
“Where do you pick the flower,” the White Queen asked, “in a garden, or in the hedges?”
“Well it isn't picked at all,” Alice explained, “it is ground ---”
“How many acres of ground?” said the White Queen.

Like these humorous conversations many Chinese riddles, word puzzles and puns are based on homonyms.