slough

"Slough" is one of those words that changes its job when its sound changes. When it rhymes with "rough" (/slʌf/), it usually means to shed or throw off something old. A snake can slough off its skin, and a person can slough off a fear, a habit, or a burden. The same form can also be a noun for dead skin or dead tissue coming away from a wound. When it sounds like "sloo" (/sluː/), it means a swampy backwater or muddy wetland, especially in North America. There is also a British literary use, pronounced /slaʊ/, in the phrase "slough of despond," which means a state of deep sadness or hopelessness.

"Slough" is a word with several lives, and the pronunciation tells you which one you are meeting.

When it rhymes with "rough" (/slʌf/), it is most often a verb meaning to shed, peel away, or get rid of something. This can be literal, as when a snake sloughs off its skin, or figurative, as when someone sloughs off an old habit, a worry, or a role that no longer fits. The same pronunciation is also used as a noun in medicine and biology for dead tissue, dead skin, or other material that is separating from a surface.

When it rhymes with "blue" (/sluː/), it names a place: a swampy backwater, muddy channel, or wetland with slow or still water. This is a common North American use, especially for quiet, marshy areas beside a river or in low ground.

There is also a form pronounced /slaʊ/, mainly in British English and older literary use. In the famous phrase "Slough of Despond," it means a state of deep misery, doubt, or hopelessness. Older dictionaries also record literal senses connected with deep mud or a muddy hollow. This pronunciation is also used for the town of Slough in England.

Taken together, the word moves between shedding, decay, mud, and despair. It can describe something falling away, a wet and heavy landscape, or the feeling of being trapped in one.