Definitions of emerald:

• noun:   the green color of an emerald
• noun:   a transparent piece of emerald that has been cut and polished and is valued as a precious gem
• noun:   a green transparent form of beryl; highly valued as a gemstone
• name:  A female given name (rare: 1 in 100000 females; popularity rank in the U.S.: #3134)
• name:  A surname (very rare: popularity rank in the U.S.: #40833)