Wig (noun)

1. A covering for the head made of real or synthetic hair worn on the head to conceal baldness or for adornment.
2. A covering for the head made of real or synthetic hair worn on the head as a part of a costume or disguise.

Origin:

From middle english "wigge".

Examples:

1. He wore a wig to conceal his baldness.
2. She wore a blonde wig to the party as part of her costume.
3. The judge is wearing a wig in court.
4. The actor put on a wig to play his role.
5. The wig was made from human hair.