Giant

1. Very large. It was a giant watermelon.
2. (mythology) Any of the race of giants in Greek mythology. Stories of giants often appear in children's fairy tales.
3. A very tall person. The basketball star was a giant of a man.
4. A tall species of a particular animal or plant. Giant squash contests are common in the farming communities.
5. A star that is considerably more luminous than a main sequence star of the same temperature. A red giant, a blue giant.
6. A very large organization. Walmart is a retail giant.