lock-and-block system

noun

Definition of lock-and-block system

British
: a railway block system in which the signals permitting a train to enter a block are locked while a train is in the block and automatically unlocked as it leaves the block

Love words?

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:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Comments on lock-and-block system

What made you want to look up lock-and-block system? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

a bell tower

Get Word of the Day daily email!

Test Your Vocabulary

Where in the World? A Quiz

  • peter bruegel tower of babel painting
  • What language does pajama come from?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

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