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

Medical Dictionary

arsenic trioxide

play
noun ar·se·nic trioxide \ˌärs-nik-, -ən-ik-\

Medical Definition of arsenic trioxide

  1. :  a poisonous trioxide As2O3 or As4O6 of arsenic that was formerly used in medicine and dentistry but has been abandoned for therapeutic purposes and is now used especially as an insecticide and weed killer—called also arsenic, arsenious acid, arsenious oxide, white arsenic




Seen and Heard

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

WORD OF THE DAY

February 13, 2016

a trying or distressing experience

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

image33683556

How much does a batman (the Turkish unit of measurement) weigh?

16.96 pounds 196.5 pounds 2.2 pounds 100 pounds
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