You can find most popular coin collecting phrases in this coin glossary.
laureate - coin design of a head crowned with a laurel wreath.
luster - a frosty and shiney appearance found on some uncirculated (mint state) coins.
legal tender - coins, paper money, or other currency issued by a government and used as money. The legal tender value of a coin is the value placed on it by the government. It may be different than the intrinsic value (bullion value) or collector value.
legend - the main lettering on a coin. For instance the phrase "United States of America"
lettered edge - The edge of a coin that has lettering on the outside of it. Usually it is raised, but sometimes incused. Most coins today have a plain edge or "reeded" edge. Having something inscribed or a design on the edge of a coin was prevalant when coins were made of precious metal. Supposedly it made it easier to detect when a coin that had some of its precious metal shaved off the edge. You'll find most all of the older gold and silver US coins will have either lettered or reeded edges. Bust Today's dime and quarter are examples of a reeded edge. See reeded edge.
Liberty Head - term used to indicate a design on the face of coins similar to the Statue of Liberty. Many different US coins have a Liberty Head design