Merriam-Webster Logo
SINCE 1828
dictionary thesaurus view recents

actinic focus

noun
Save Word

Definition of actinic focus

: the focus at which the chemically most effective rays as distinguished from the visually most effective are brought together (as by a lens)

— called also chemical focus

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!

First Known Use of actinic focus

1853, in the meaning defined above

Keep scrolling for more

Learn More about actinic focus

Time Traveler for actinic focus

Time Traveler

The first known use of actinic focus was in 1853

See more words from the same year

Statistics for actinic focus

Cite this Entry

“Actinic focus.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/actinic%20focus. Accessed 6 December 2019.

Comments on actinic focus

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

Show Comments  Hide Comments 

WORD OF THE DAY

gingerly

Listen to the pronounciation of gingerly

very cautious or careful

Get Word of the Day daily email!

Test Your Vocabulary

Semantic Drift Quiz

  • a twisty river
  • Which of the following was once a synonym for fun?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Citation

Test Your Knowledge - and learn some interesting things along the way.

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