“proton pump”

We have one entry that includes the term proton pump.

proton pump inhibitor

noun

: any of a group of drugs that inhibit the activity of pumps transporting hydrogen ions across cell membranes and are used to inhibit gastric acid secretion

See the full definition

Word of the Day

Listen to the pronunciation of oblivion

See Definitions and Examples »

Test Your Vocabulary

Challenging Words You Should Know

  • hedgehog reading a book
  • Often used to describe “the march of time,” what does inexorable mean?
Name That Thing

You know what it looks like… but what is it called?

TAKE THE QUIZ
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.

Pick the best words!

PLAY
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
little boy with a magnifying glass looking at footprints
Quiz: Spot the Misspelled Word! Think you can detect a spelling error from a mile...
See All