German

Noun

Perpetuum mobile n ‎(genitive Perpetuum mobile, plural Perpetuum mobiles or Perpetua mobilia)

1. perpetual motion machine

Czech

Noun

perpetuum mobile n

1. perpetual motion machine

Dutch

Etymology

From Latin perpetuum (neutral inflection of perpetuus 'perpetual') + Latin mobile (neutrum of mobilis 'mobile, moving', used as a noun)

Noun

perpetuum mobile n ‎(plural perpetuum mobiles, diminutive pepetuum mobileetje n)

1. A perpetual motion machine (hypothetical contraption capable of remaining in perpetual motion without needing any additional energy ever)
2. (figuratively) Something impossible, a figment of one's imagination