Here are the definitions for the letter "m"

Malt extract

The condensed wort from a mash, consisting of maltose, dextrins, and other dissolved solids in the form of powdered suger or syrup. It can be reconstituted with water for fermentation.

Malt liquor

A type of beer of relatively high alcohol content (7 to 8 percent by volume), as defined in the United States.

Malting

The process of converting the starches of barley grain to sugars (maltose) in preparation for fermentation. The barley is first soaked in water, germinated, and then kilned.

Maltose

The water-soluble, fermentable malt sugar.

Mash

The malted barley-water mixture whereby the sugars are released, or as a verb, the process of creating this mixture.

Mash tun

A tank for preparing the mash.

Mead

Meads are produced by the fermentation of honey, water, yeast and optional seasonings such as fruit, herbs, and/or spices. They are classified by their final specific gravity as dry, medium, or sweet.

Medicinal

Having a chemical or phenolic taste resulting from wild yeast, contact with plastic, or sanitizer residue.

Metallic

Term associated with over-aged beer.

Microbrewery

Small brewery generally producing less than 15,000 barrels per year. Sales primarily off-premises.

Mouthfeel

A sensation derived from the body or viscosity of a beer, ranging from thin to full.

Musty

Having a moldy, mildewy flavor and aroma, due to cork or brew spoilage.