There are various words relating some chemical or technical terms, constituting more than thousand letters but in this list of Topyaps, we are referring only those words which are enlisted in dictionaries. Also, there are lot of words with equal number of alphabets but here we have mentioned only one word for unique number of alphabets.
10. Otorhinolaryngological (22 letters):
Branch of medical science which deals with the treatment of head, neck, ear, throat and nose disorders.
9. Thyroparathyroidectomized (25 letters):
The process of cutting out Thyroid and Parathyroid glands.
8. Radioimmunoelectrophoresis (26 letters):
Immunoelectrophoresis (Electrophoresis to separate antigens and antibodies) using antigens or antibodies labeled with radioisotopes.
7. Honorificabilitudinitatibus (27 letters):
This is the longest word ever applied by Shakespeare which stands for “The state of being able to achieve honours”.
6. Antidisestablishmentarianism (28 letters):
Evolved in 1838 in Britain, it signifies opposition to proposals for the disestablishment of the Anglican Church.
Process of determining that something is absolutely valueless.
4. Pseudopseudohypoparathyroidism (30 letters):
A genetic disorder which closely imitates the indications but not the effects of pseudohypoparathyroidism and, thus it has mild or no manifestations of hypoparathyroidism or tetanic convulsions.
3. Supercalifragilisticexpialidocious (34 letters):
Something to say when you have nothing to say.
2. Hepaticocholangiocholecystenterostomies (39 letters):
A surgical creation of a connection between the gall bladder and a hepatic duct and between the intestine and the gall bladder.
1. Pneumonoultramicroscopicsilicovolcanoconiosis (45 letters):
Lung disease caused by the inhalation of crystalline silica dust.