What is the longest English word?
We do have genuine (if rather obviously deliberate) examples in our files of antidisestablishmentarianism (28 letters) and floccinaucinihilipilification (29 letters), which are listed in some of our larger dictionaries. Other words (mainly technical ones) recorded in the complete Oxford English Dictionary include:
otorhinolaryngological (22 letters),
immunoelectrophoretically (25 letters),
psychophysicotherapeutics (25 letters),
thyroparathyroidectomized (25 letters),
pneumoencephalographically (26 letters),
radioimmunoelectrophoresis (26 letters),
psychoneuroendocrinological (27 letters)
hepaticocholangiogastrostomy (28 letters),
spectrophotofluorometrically (28 letters),
pseudopseudohypoparathyroidism (30 letters).