Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Medical
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

actinometer

play
noun ac·ti·nom·e·ter \ˌak-tə-ˈnä-mə-tər\

Definition of actinometer

  1. :  any of various instruments for measuring the intensity of incident radiation; especially :  one in which the intensity of radiation is measured by the speed of a photochemical reaction

ac·ti·no·me·tricplay \-nō-ˈme-trik\ adjective
ac·ti·nom·e·tryplay \-ˈnä-mə-trē\ noun


1833

First Known Use of actinometer

1833


Medical Dictionary

actinometer

play
noun ac·ti·nom·e·ter \ˌak-tə-ˈnäm-ət-ər\

Medical Definition of actinometer

  1. :  any of various instruments for measuring the intensity of incident radiation; especially :  one in which the intensity of radiation is measured by the speed of a photochemical reaction

  2. ac·ti·no·me·tric \-nō-ˈme-trik\play adjective
    ac·ti·nom·e·try \-ˈnäm-ə-trē\play noun, plural ac·ti·nom·e·tries




Learn More about actinometer


Seen and Heard

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

WORD OF THE DAY

February 10, 2016

to put in good humor

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

image1037863653

Which of the following refers to thin, bending ice, or to the act of running over such ice?

spindrift pince-nez duvet kittly-benders
Name That Thing

10 quick questions: hear them, spell them, and see how your skills compare to the crowd.

TAKE THE QUIZ
SCRABBLE® Sprint

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

TAKE THE QUIZ