noun

• (arithmetic) A ratio of two numbers (numerator and denominator), usually written one above the other and separated by a horizontal bar called the vinculum or, alternatively, in sequence on the same line and separated by a solidus (diagonal bar).
  "Gasoline prices show the mill as a fraction, for example $3.59+⁹⁄₁₀."
• (chemistry) A component of a mixture, separated by fractionation.
• (Christianity) In a eucharistic service, the breaking of the host.
  "[…] The bread, when it is consecrated and made sacramental, is the body of our Lord; and the fraction and distribution of it is the communication of that body, which died for us upon the cross."
• (archaic) The act of breaking, or state of being broken, especially by violence.
  "Neither can the natural body of Christ be subject to any fraction or breaking."

verb

• (transitive) To divide or break into fractions.
• (transitive) To fractionate.