What was known in the UK in World war II as "the Matilda"?

Question

During World War II the US and UK armies used bodies of, respectively, over 54,000 and 250,000 what, as part of their communication and/or delivery systems?

Answer 1

The A12 gun-armed infantry tank
The Matilda was designed beginning in 1936 as a counterpart to the tank Matilda I, which was withdrawn in 1940, and was initially known as A12, the Matilda II or Matilda senior.