The Collaborative International Dictionary
Undersphere
Undersphere \Un"der*sphere`\, n.
A sphere which is smaller than, and in its movements subject to, another; a satellite.
An inferior sphere, or field of action.
Wiktionary
undersphere
n. 1 A sphere which is smaller than, and in its movements subject to, another; a satellite. 2 An inferior sphere, or field of action.