The angle between the plane of the Earth's orbit (the ecliptic) and the plane of the Earth's equator. This angle varies from about 22° to 24.5° over a period of 40,000 years. Currently the obliquity is about 23.5° . This "tilt" of the Earth's axis is responsible for the seasons.
OBLIQUITY
Meaning of OBLIQUITY in English
Weather and meteorology English vocabulary. Английский словарь погоды и метеорологии . 2012