perpetuüm mobile

Etymology
, neuter substantive from the adjectives  +, having the literal sense “perpetual mover”.

Noun

 * 1) perpetual motion machine, perpetuum mobile hypothetical contraption capable of remaining in perpetual motion without ever needing any additional energy
 * 2)  an impossible thing, a figment of one’s imagination
 * 1)  an impossible thing, a figment of one’s imagination
 * 1)  an impossible thing, a figment of one’s imagination