The Rest Is Science
The Rest Is Science

How Many Words Do You ACTUALLY Know?

June 10, 2026 • 51m

Summary

⏱️ 8 min read

Overview

Hannah Fry and Michael Stevens explore vocabulary testing through VocabOwl, a website created by listener Jake that estimates how many words you know. They compare their results, discuss fascinating obscure words, and dive into questions about internal monologues, talking to oneself, and the quirks of human cognition. The episode reveals surprising personal insights about how each host processes thoughts differently.

VocabOwl: Testing Your Vocabulary

Jake, a listener inspired by a previous episode about vocabulary size, created VocabOwl—a website that tests your knowledge of English words. The test presents 100 words across five difficulty levels (core basics through grandmaster) with multiple-choice definitions. Hannah and Michael both took the test, discovering they know remarkably similar amounts with Hannah scoring slightly higher at 73,400 words versus Michael's 72,250 words out of approximately 171,476 words in current English use.

  • VocabOwl was created by listener Jake, inspired by a previous episode discussion about vocabulary size
  • The Oxford English Dictionary estimates there are 171,476 words in current use, but most people only know 15,000-35,000 words
  • The test covers 100 words across five difficulty categories: core basics, intermediate, advanced, expert, and grandmaster
  • Hannah scored an estimated 73,400 words while Michael scored 72,250 words
  • Michael got 10 words wrong while Hannah got 9 wrong, but in different difficulty ranges
" I didn't know it would get harder. I was like, I know every word. "
" You know a thousand more words than me, approximately. What are they? Who knows? Probably British ones like chim-chim-churri and... Jiminy Cricket. "

Vocabulary Mistakes and Obscure Words

Hannah and Michael share the words they got wrong on the test, revealing fascinating linguistic traps and archaic terms. Many of their mistakes came from words that sound like they should mean one thing but actually mean the opposite, such as "innervate" (meaning to drain rather than energize) and "noisome" (meaning stinky, not noisy). They also encountered ridiculously obscure words like "zenzizenzizenzic" (the eighth power of a number) and "eucalagon" (a neighbor whose house is on fire).

  • Hannah thought 'zenith' meant highest point but it actually means strongest point or peak
  • Both got 'zephyr' wrong—Michael chose violent storm wind instead of soft gentle breeze
  • 'Lugubrious' means looking or sounding sad and dismal, not happy—both got this wrong
  • 'Unctuous' means excessively or irritatingly flattering, like a salesperson, not delicious or dry
  • 'Innervate' means to cause someone to feel drained of energy, the opposite of what it sounds like
  • 'Zenzizenzizenzic' is an archaic word meaning the eighth power of a number, from medieval Italian
  • 'Eucalagon' means a neighbor whose house is on fire, from a character in the Iliad
" I guess that it meant dry and rough and rude. Unctuous. Oh, this drink is unctuous. But no, to be unctuous means to be like a salesperson is unctuous. They're like, oh, you have such great tastes. "
" If you start using that word when you're describing to the eighth power, people are going to think you're a bit of a zinzi, zinzi. "

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