Apart from being one of the longest words in the dictionary, hippopotomonstrosesquippedaliophobia is the phobia or fear of long words. Isn’t that ironic.
According to Healthline, feelings of shame or fear of ridicule for mispronouncing long words may cause distress or anxiety. Hippopotomonstrosesquippedaliophobia as a phobia isn’t officially recognized as a diagnosis, so more research is needed.