What is Polysemy and How Does it Differ From Homonymy?

There are numerous word types that by semantic definition are hard to define without context. Included in this category are polysemes and homonyms. Traditionally, polysemes and homonyms are similar in that they each have variations of meaning for phonologically identical words.

Homonyms can be further broken down into homophones; words that are pronounced identically though spelled differently, and homographs; words that are pronounced and spelled identically. In both instances of homonymy the requirement is for the common words to have unrelated meanings.

Homophones:

bare - to uncover

bear - the mammal

Homographs:

bank - the financial institute

bank - the side of a river

In the case of polysemy, the reference is to a single word with different senses of the same basic meaning. Polysemes are also distinguished from homonyms because they are etymologically related.

Polysemes:

crawl - to move slowly on hands and knees
crawl - to move slowly in traffic
crawl - to be covered with moving things
crawl - to swim the crawl