Yes, the Titin example is completely ridiculous. On the one hand, the protein Titin is one of the longest sequences. However you can form a 'word' out of any protein or DNA (or other macromolecue or polymer) this way.

The key problem for me is that you would never refer to any polypeptide this way in a sentence. It would be like referring to a piece of software by concatenating its source code into one long 'word'. Meaningless.

That's not a word that's a polypeptide sequence. How and why did that get entered into Wikitionary to begin with? It doesn't belong there.

Next up will they start recording the corresponding DNA sequences as "words" that are a synonym?