What is gibbous definition?

The term gibbous refers to a phase of the moon or a planet that appears to be more than half but less than fully illuminated by the Sun. When the illuminated portion is increasing, it is referred to as a waxing gibbous, and when it is decreasing, it is referred to as a waning gibbous. The term is also used to describe something that is bulging or swollen, such as a plant or animal tissue. In astronomy, gibbous is often used to describe the shape of the moon or a planet when viewed through a telescope.