SINCE 1828
dictionary
thesaurus

photonasty

noun
Save Word
pho·​to·​nas·​ty
plural -es

Definition of photonasty

: a nastic movement that is associated with changes in light intensity

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

History and Etymology for photonasty

International Scientific Vocabulary phot- + -nasty; probably originally formed as German photonastie

Learn More About photonasty

Dictionary Entries Near photonasty

photonastic

photonasty

photonegative

See More Nearby Entries 

Statistics for photonasty

Cite this Entry

“Photonasty.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/photonasty. Accessed 2 Jul. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

WORD OF THE DAY

apposite

Listen to the pronunciation of apposite

See Definitions and Examples »

Test Your Vocabulary

Great Words for Scrabble

  • scrabble tiles that read scrabble quiz
  • Which of the following Q-without-U words means the number five in cards or dice?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play
Ask the Editors
Word Games