Attaining a higher place; taking, or moving in, an upward direction; appearing above the horizon; ascending; as, the rising moon.
More than; exceeding; upwards of; as, a horse rising six years of age.
In natal astrology, the sign on the Ascendant (first house cusp). In horary astrology, the sign rising in the east at the time in question. Rotational inertia: the tendency of a spinning body's spin axis to remain pointed in the same direction in space. As long as a spinning body is not acted upon by an outside force its spin axis will remain forever pointed in the same direction in space relative to the stars! This is how gyroscopes form inertial guidance systems for planes, submarines and spacecraft. These vehicles constantly refer to a gyroscope's fixed and rigid orientation in space in order to navigate and maintain their bearings (see pages 89 and 90 in " You and the Universe").
a movement upward; "they cheered the rise of the hot-air balloon"
A planet is said to be rising, or ascending, when moving via the ascendant between the fourth and tenth cusps, i.e. in the eastern hemisphere of the chart. Some modern astrologers only consider a planet to be rising if actually placed in the first house, where its strength is accentuated because angular. [It's a moot point as to whether a planet in the mid-heaven should be described as "rising", or simply "elevated". Certainly it is angular and thus strengthened.