SINCE 1828

An Encyclopædia Britannica Company

Medical Dictionary

petrotympanic fissure

noun

medical Definition of petrotympanic fissure

:a narrow transverse slit dividing the glenoid fossa of the temporal bone — called also Glaserian fissure

Seen and Heard

What made you want to look up petrotympanic fissure? Please tell us where you read or heard it (including the quote, if possible).

show

WORD OF THE DAY

euphony

play

pleasing or sweet sound

Words at Play

alt-59e50f5a357b4

'Spox' May Go On The Record

From newsroom lingo to the mainstream

alt-59e506c5c02ae

C'mon, Of Course 'Myriad' Is a Noun

For a myriad of reasons

alt-59e12097b419d

'Gamut' and 'Gambit' (and 'Gauntlet' Too)

Know when to use (or run) each.

17 English Words that Come From Japanese

Some borrowed words don't get returned

Ask the Editors

video-title-words-of-the-year-1066

Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless

Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals

Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

knupfer-painting-solon-before-croesus

Forms of Government Quiz

Name that government! Or something like that.

Take the quiz

rembrandt-painting-a-young-scholar-and-his-tutor

Original Meanings Quiz

A quiz for the pedantic and those annoyed by them!

Take the quiz

True or False?

Test your knowledge - and maybe learn something along the way.

Take the quiz

Dictionary Devil

Dictionary Devil

The dictionary has been scrambled—can you put it back together?

Play the game