According to some, the formal name for the protein titin (‘not to be confused with Tintin’) is, with 189,819 letters, the longest English word in existence. At such a size, it seems to take on almost deity-like characteristics, as shown on a Wikipedia discussion page where it is respectfully referred to as simply ‘the word’ during heated arguments over whether to include it in the titin page or not. As a colleague of mine informed me, this is why scientists shouldn’t be allowed near language.

In case you think that such a formulaic construction has only a dubious claim to the title, there’s a roundup of some of the other (mostly contrived) candidates here, of which I quite like floccinaucinihilipilification – ‘the action or habit of estimating as worthless’.