viva : Idioms & Phrases

• (Mech.), the principle that the difference between the aggregate work of the accelerating forces of a system and that of the retarding forces is equal to one half the vis viva accumulated or lost in the system while the work is being done.

Webster 1913

• L. (Mech.), living force; the force of a body moving against resistance, or doing work, in distinction from vis mortua, or dead force; the kinetic energy of a moving body; the capacity of a moving body to do work by reason of its being in motion. See Kinetic energy, in the Note under Energy. The term vis viva is not usually understood to include that part of the kinetic energy of the body which is due to the vibrations of its molecules.

Webster 1913

• noun an examination conducted by spoken communication
  viva; oral examination; oral; oral exam.
  
• adverb orally
  by word of mouth.
  
  • I heard it viva voce

WordNet

Vi"va vo"ce

Etymology

L.

Definitions

1. By word of mouth; orally.

Webster 1913

• adjective satellite expressed orally
  word-of-mouth.
  
  • a viva-voce report
  • the film had good word-of-mouth publicity

WordNet