Select the INCORRECTLY spelt word.

Robbust

The incorrectly spelled word is Robbust. The correct spelling is Robust.

• Xylophone is spelled correctly. It is a musical instrument consisting of a series of wooden bars graduated in length to produce the musical scale, supported on belts of straw or felt, and sounded by striking with two small wooden hammers.
• Oligopoly is spelled correctly. It is a market structure in which a small number of sellers control a large share of the market.
• Robust is spelled correctly. It means strong and healthy.
• Zenith is spelled correctly. It means the highest point or point of greatest success.