Acorn (noun)

1. The fruit of the oak tree, a nut with a hard shell and a pointed tip.
2. The nut of an oak tree.

Origin:

From the old english word "æcern", which is derived from the proto-germanic *akran and proto-indo-european *h₂éǵros.

Examples:

1. Acorns are an important food source for wildlife such as deer, squirrels and jays.
2. Acorns are a traditional food for some indigenous people.
3. Acorns can be collected, shelled, ground and used to make flour.
4. Acorns were used by early humans as a source of food.
5. Acorns are an important symbol in many cultures and have been used as a decorative motif in art and architecture.