noun an·nu·a·tion \ˌanyəˈwāshən\

Definition of annuation



  1. 1 :  annual variation in the presence or absence or the abundance of particular members of a plant community usually relatable to annual climatic variation — compare aspection

  2. 2 :  ecological observations made over a period of years

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.

Join MWU now and get access to America’s largest dictionary, with:

  • 300,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Origin and Etymology of annuation

1annu(al) + -ation

First Known Use: 1939

Seen and Heard

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


to cast off or become cast off

Get Word of the Day daily email!