SINCE 1828

An Encyclopædia Britannica Company

Medical Dictionary

isoquinoline

play

noun iso·quin·o·line \ˌī-sō-ˈkwin-^əl-ˌēn\

Medical Definition of isoquinoline

: a low-melting nitrogenous base C₉H₇N that is associated with its isomer quinoline in coal tar and that is the parent structure in many alkaloids (as narcotine and papaverine)

Seen and Heard

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

show

WORD OF THE DAY

fester

play

to become worse as time passes

Words at Play

alt-5978cb55e8ba5

The Grammatical History of 'Awaken'/'Awoken'/'Awakened'

Or you can just go back to bed.

alt-59775cb5d7779

Words We're Watching: 'Aquafaba'

Don't dump out the bean water just yet...

Words About Word Play

Don't just eat your words—play with them!

alt-596f95fe451e7

'Drought' & 'Drouth' Take Us Back In Time

A variant spelling with a long history

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

The Emoji Quiz

Think you’re an emoji 👓 expert? Let’s see 🤔

Take the quiz

A Game of Thrones Word Quiz

In the Game of Thrones quiz, you learn some new vocabulary. (It’s quite safe, really. You will not die.)

Take the quiz

Name That Thing

Name That Thing

Test your visual vocabulary with our 10-question challenge!

Take the quiz

Citation

Do you know the person or title these quotes describe?

Play the game