Medical Definition of valacyclovir
: a prodrug of acyclovir that is administered orally in the form of its hydrochloride C13H20N6O4·HCl to treat shingles, genital herpes, and cold sores — see valtrex
Test Your Vocabulary
Slippery Words Quiz—Changing with the Times
- What is an earlier meaning of nice?

Test your vocabulary with our 10-question quiz!
TAKE THE QUIZ
Anagram puzzles meet word search.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
Slippery Words Quiz—Changing with the Times
Do you know these earlier meanings of words?
Take the quizWords of Snow and Ice Quiz
A selection of words from the chillier parts of t...
Take the quizHow Strong Is Your Vocabulary?
Test your vocabulary with our 10-question quiz!
Take the quizSCRABBLE® Sprint
SCRABBLE® fans, sharpen your skills!
Play the game
Share valacyclovir