You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.
Start your free trial today and get unlimited access to America's largest dictionary, with:
Share header course
Cite this Entry
“Header course.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/header%20course. Accessed 24 Jan. 2022.
See Definitions and Examples »
Get Word of the Day daily email!
Farm Idioms Quiz
Test your knowledge - and maybe learn something along the way.
A daily challenge for crossword fanatics.
Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!
Top 10 Latin Phrases
When you are left to your own rhetorical devices.
Can you care fewer?
What's (another word for) the big idea?
A simple trick to keep them separate
How 'literally' can mean "figuratively"
How to use a word that (literally) drives some pe...
The awkward case of 'his or her'
A warm and toasty quiz to nestle into
Take the quiz
New Year, Recondite Vocabulary
Test your knowledge - and maybe learn something a...