SINCE 1828

An Encyclopædia Britannica Company

Medical Dictionary

arrhenotoky

noun ar·rhe·not·o·ky \ ˌar-ə-ˈnät-ə-kē \

medical Definition of arrhenotoky

plural arrhenotokies

:parthenogenesis in which only males are produced — compare deuterotoky, thelytoky

Seen and Heard

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

show

WORD OF THE DAY

malign

play

to speak evil of

Words at Play

alt-59e77dc36c593

The Origins of 'Lobbyist'

From the front hallways to the back rooms

alt-59e673567065d

The History of the Word 'Terrorism'

Noah Webster first entered the term in 1840

alt-59e65152518a6

'Regimen' vs. 'Regiment'

The rule of thumb for words about rules

alt-59e50f5a357b4

'Spox' May Go On The Record

From newsroom lingo to the mainstream

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

one-green-toy-robot-amidst-many-red-toy-robots

The Exceptions Quiz III

Which of these things doesn't belong?

Take the quiz

knupfer-painting-solon-before-croesus

Forms of Government Quiz

Name that government! Or something like that.

Take the quiz

True or False?

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

Take the quiz

SCRABBLE® Sprint

SCRABBLE® Sprint

SCRABBLE® fans, sharpen your skills!

Play the game