Definition of lactose
: a disaccharide sugar C12H22O11 that is present in milk and yields glucose and galactose upon hydrolysis and yields especially lactic acid upon fermentation
Test Your Vocabulary
The Great British Vocabulary Quiz
-
- Named after Sir Robert Peel, what are British police called?

Test your vocabulary with our 10-question quiz!
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Share lactose
Time Traveler for lactose
The first known use of lactose was in 1847
See more words from the same year