What is the longest word in the English language?

The longest word in the English language is a chemical name for the protein Titin. The name is made up of 189,819 letters and takes over three hours to pronounce. The name of this protein starts with Methionylthreonylthreonyl... and goes on for 1,913 amino acids.

While the name of the protein Titin is widely considered to be the longest word in English, there are other lengthy words that are often mentioned. These include pneumonoultramicroscopicsilicovolcanoconiosis, a lung disease caused by the inhalation of fine silica dust, and floccinaucinihilipilification, which means the act or habit of estimating something as worthless.