airlock: an airlock is used on the secondary fermentor(s) to ensure that no oxygen/particles/bacteria reach the wine as it is fermenting, and to make sure that the CO2 produced during fermentation can get out. It's a sort of one-way valve. If oxygen gets in, the alcohol can oxidize into acetic acid--vinegar. Airlocks are inexpensive, and the most simple ones are just a balloon over the top of the fermentation vessel.
campden tablets: These tablets contain sulfurous compounds that will kill off wild yeasts and bacteria when crushed and added to your fresh juices. They can often be avoided by using heat and boiling to kill of the unwanted bacteria and yeast, but are a convenient winemaking tool.
country wine: This is a broad term for wines made from fruits other than grape.
hydrometer: this tool is used to measure the specific gravity of a liquid, which in turn can tell you how much sugar a solution contains, and how much alcohol it should yield
must: this is the mixture of your fruits and water and sugar and... Basically your fermentable liquid.
pectic enzyme: also called pectinase. breaks down the gelatinous carbohydrate pectin so that anything that's making your wine cloudy can settle out. best if used before fermentation or early in fermentation.
primary fermentor: this is the first fermentation container. Everything goes in here, and it often gets gunky, bubbly, and messy. It should usually be one gallon larger than the quantity of wine that you are making so that the mixture has room to bubble up often fermentation occurs for less than a week in this container.
racking: racking is simply the transfer of your wine from one fermentor to another, leaving sediment, yeast, and gunk at the bottom of the old container. some wines require only one or two rackings, while others may require many.
secondary fermentor: this is the fermentation vessel where your wine will do a longer fermentation. This vessel is sized according to how much wine you're making--perhaps a five gallon glass or plastic carboy or a one gallon milk jug. It is sealed with an airlock so that your alcohol does not oxidize to acetic acid--vinegar.
tannins: tannins are natural components of plants. they generally come from the woody parts of plants and fruits like the skins, pits, and stems. Too many tannins can create a very bitter, off-tasting wine, but they are also responsible for that wonderful puckery taste you get from red wines and many country wines. The astringency that they can add to wine is often extremely beneficial
yeast energizer: yeast energizer gives your yeast an extra boost and can often restart stuck fermentations
yeast nutrients: Yeasts are eukaryotes just like humans! They require nutrients like nitrogen that many fruits and vegetables don't have, just like growing plants require nitrogenous fertilizers. Nutrients allow yeasts to flourish, and help prevent stuck fermentations. Usually used in a 1 teaspoon per gallon of wine ratio.