To save this word, you'll need to log in.
Definition of acid-free
: not containing acid : having a neutral or alkaline pH
acid-free paper Every evening, trained volunteers will place any personal items or memorabilia left at the replica wall in archival folders or acid-free boxes.— Brian Burnes, Kansas City Star, 22 Sept. 2010
Keep scrolling for more
Comments on acid-free
What made you want to look up acid-free? Please tell us where you read or heard it (including the quote, if possible).
Test Your Vocabulary
The Eponym Quiz
- Which is the best synonym of bowdlerize?
Can you spell these 10 commonly misspelled words?
TAKE THE QUIZ
Test Your Knowledge - and learn some interesting things along the way.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
- The Eponym Quiz
Do you know these words that come from names?
Take the quiz - Liar, Liar Quiz
Test your knowledge of words for lies, liars, and those being lied to. In other words, everyone.
Take the quiz - Spell It
Can you spell these 10 commonly misspelled words?
Take the quiz - Syn City
Build a city of skyscrapers—one synonym at a time.
Play the game
Share acid-free
Time Traveler for acid-free
The first known use of acid-free was in 1885
See more words from the same year