It is called a "loonie" because on the tails side of the coin in the imprint of a Loon. A bird commonly found in the northern wilderness. FYI; the two dollar coin is called a "two-nie"
Clad coins have copper and nickel in the middle. They were made in the US after 1964. 1964 was the last year that the US made solid silver currency. I don't know what uc means, but unc is short for...
Gold coins are gold in color. They are made of gold. They came from the US but they were made many years ago. They also came from other world countries.