English vocabulary is vast. It is pretty difficult to make a list of longest words from the dictionary. However, we are making an attempt — following are the 25 longest words in English dictionary. We are also giving the letter count and meanings as well. We hope you don’t develop hippopotomonstrosesquippedaliophobia!
- Pneumonoultramicroscopicsilicovolcanoconiosis (45 letters) – A lung disease caused by inhaling very fine silicate or quartz dust.
- Hippopotomonstrosesquippedaliophobia (33 letters) – Fear of long words.
- Supercalifragilisticexpialidocious (34 letters) – A made-up word, often cited as one of the longest words in the English language; used to describe something fantastic.
- Pseudopseudohypoparathyroidism (30 letters) – An inherited disorder that closely simulates the features but not the consequences of pseudohypoparathyroidism.
- Floccinaucinihilipilification (29 letters) – The act or habit of describing or regarding something as unimportant.
- Antidisestablishmentarianism (28 letters) – Opposition to the withdrawal of state support for an established church, especially the Anglican Church in 19th-century England.
- Electroencephalographically (27 letters) – In a manner pertaining to the electroencephalogram, a test to measure electrical activity in the brain.
- Microspectrophotometrically (25 letters) – Pertaining to the use of a microspectrophotometer, an instrument for measuring the spectra of microscopic samples.
- Spectrophotofluorometrically (25 letters) – Relating to a method of measuring the emission spectrum of a substance.
- Psychoneuroimmunologically (25 letters) – Pertaining to the interactions between the nervous system and the immune system.
- Dichlorodiphenyltrichloroethane (31 letters) – A synthetic insecticide commonly known as DDT.
- Uncharacteristically (20 letters) – In a way that is not typical or usual.
- Thyroparathyroidectomize (24 letters) – To surgically remove the thyroid and parathyroid glands.
- Otorhinolaryngological (22 letters) – Pertaining to the ear, nose, and throat.
- Anticholinesterase (17 letters) – An agent that inhibits the action of cholinesterase, thereby increasing the action of acetylcholine.
- Counterdemonstration (19 letters) – A demonstration organized in opposition to another demonstration.
- Deinstitutionalization (20 letters) – The process of replacing long-stay psychiatric hospitals with less isolated community mental health services.
- Disadvantageousnesses (21 letters) – The quality of creating a disadvantage.
- Electrocardiographically (23 letters) – In relation to the electrocardiogram.
- Establishmentarianism (20 letters) – The belief in the establishment, or the dominant groups in society.
- Immunoelectrophoretically (24 letters) – By means of immunoelectrophoresis, a method of analyzing mixtures of proteins.
- Indistinguishableness (20 letters) – The quality of being difficult to differentiate or tell apart.
- Irrefragableness (16 letters) – The quality of being impossible to refute or dispute.
- Lexicographically (17 letters) – In relation to alphabetical order.
- Microminiaturizations (20 letters) – The act or process of making something extremely small.
If you want to be a English words spelling champion, make sure to master the above words! In the comments, please let us know any other long English words that should be part of this list.