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Answer:</h2>
<em>Pneumonoultramicroscopicsilicovolcanoconiosis</em>: This is a word that is thought of to be similar in meaning to one of the lung's diseases called silicosis. This disease is caused by inhaling sand dust and similar particles.
<u>In a sentence: </u>
The man died of <em>pneumonoultramicroscopicsilicovolcanoconiosis</em>
<em>Hippopotomonstrosesquippedaliophobia</em>: This is a noun and also one of the longest words. It is thought to mean the fear for long words.
<u>In a sentence: </u>
I hate long words, I guess I have <em>hippopotomonstrosesquippedaliophobia.</em>
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<em>Supercalifragilisticexpialidocious: </em>It is used to express extreme excitement or to describe something as being very good or great.
<u>In a sentence: </u>
The meal tastes <em>supercalifragilisticexpialidocious.</em>
<em>Pseudopseudohypoparathyroidism: </em>It is a word used to describe a disorder, usually inherited, that makes tissues and joints to be hard.
<u>In a sentence: </u>
John and Doe are suffering from <em>pseudopseudohypoparathyroidism.</em>
<em>Floccinaucinihilipilification: </em>This is a word that is used to describe the action of deciding that something is really worthless.
<u>In a sentence: </u>
She was very hurt by her brother's <em>floccinaucinihilipilification </em>of her great singing skills.
<em>Antidisestablishmentarianism: </em>A word that is used to describe the opposition to the belief that no official relationship should exist between the government of a country and the national Church (established church) of that country.
<u>In a sentence: </u>
<em>Antidisestablishmentarianism </em>is overhyped.