Three monosyllabic m words figure prominently in the Holmes stories, but are seldom heard in American English. Appropriately enough, they share origins in Old English, and two of them are labeled as "chiefly British."
Moor
Definition:
chiefly British : an expanse of open rolling infertile land
About the word:
The setting of “Silver Blaze” and The Hound of the Baskervilles is Dartmoor, a region of moorland in southwestern England. The moor itself becomes an atmospheric and dangerous character in the stories.
Mere
Definition:
chiefly British : an expanse of standing water : lake, pool
About the word:
Mere as an adjective (a mere scratch; a mere boy in his teens) comes from Latin and is unrelated to the noun mere that means “lake.” Holmes himself uses mere and lake interchangeably in “The Problem of Thor Bridge”:
The papers may ask why the mere was not dragged in the first instance, but it is easy to be wise after the event, and in any case the expanse of a reed-filled lake is no easy matter to drag unless you have a clear perception of what you are looking for and where.
Mire
Definition:
1: wet spongy earth (as of a bog or marsh)
2: heavy often deep mud or slush
3: a troublesome or intractable situation
About the word:
Mire comes from a Scandinavian word that is related to the Old English root that gave us moss and marsh. In The Hound of the Baskervilles, mire is also used as part of a place name, the Grimpen Mire, where Stapleton describes a wild pony sinking, as if in quicksand:
“It's gone!” said he. “The mire has him. Two in two days, and many more, perhaps, for they get in the way of going there in the dry weather, and never know the difference until the mire has them in its clutches. It's a bad place, the great Grimpen Mire.”