Word Study
self-motion
CIDE DICTIONARY
self-motion, n.
Motion given by inherent power, without external impulse; spontaneous or voluntary motion. [1913 Webster]
"Matter is not induced with self-motion." [1913 Webster]
OXFORD DICTIONARY
self-motion, n. motion caused by oneself or itself, not externally.
Derivative
self-moving adj.
For further exploring for "self-motion" in Webster Dictionary Online