What does "eighth" mean?

Eighth: Consisting of one of eight equal divisions of a thing. Eighth note (Mus.), the eighth part of a whole note, or semibreve; a quaver.

Additional senses

  1. 2.The quotient of a unit divided by eight; one of eight equal parts; an eighth part.
  2. 3.(Mus.) The interval of an octave.

Sources