The terms Waxing and Waning refer to the phase of a planet or moon.   The term Waxing is given to a celestial body if the phase is in the process of increasing toward full.  Waning is given if the phase is decreasing from full.  The image above was captured as the Moon was Waxing to full.  The Moon, in this image, is also termed as Gibbous which is a phase of more than half but less than full.