1. a fraction with a numerator smaller than the denominator;

The Collaborative International Dictionary of English v.0.48:

Fraction \Frac"tion\, n. [F. fraction, L. fractio a breaking, fr. frangere, fractum, to break. See Break.] 1. The act of breaking, or state of being broken, especially by violence. [Obs.] [1913 Webster] Neither can the natural body of Christ be subject to any fraction or breaking up. --Foxe. [1913 Webster] 2. A portion; a fragment. [1913 Webster] Some niggard fractions of an hour. --Tennyson. [1913 Webster] 3. (Arith. or Alg.) One or more aliquot parts of a unit or whole number; an expression for a definite portion of a unit or magnitude. [1913 Webster] Common fraction, or Vulgar fraction, a fraction in which the number of equal parts into which the integer is supposed to be divided is indicated by figures or letters, called the denominator, written below a line, over which is the numerator, indicating the number of these parts included in the fraction; as 1/2, one half, 2/5, two fifths. Complex fraction, a fraction having a fraction or mixed number in the numerator or denominator, or in both. --Davies & Peck. Compound fraction, a fraction of a fraction; two or more fractions connected by of. Continued fraction, Decimal fraction, Partial fraction, etc. See under Continued, Decimal, Partial, etc. Improper fraction, a fraction in which the numerator is greater than the denominator. Proper fraction, a fraction in which the numerator is less than the denominator. [1913 Webster]The Collaborative International Dictionary of English v.0.48:

Proper \Prop"er\, a. [OE. propre, F. propre, fr. L. proprius. Cf. Appropriate.] [1913 Webster] 1. Belonging to one; one's own; individual. "His proper good" [i. e., his own possessions]. --Chaucer. "My proper son." --Shak. [1913 Webster] Now learn the difference, at your proper cost, Betwixt true valor and an empty boast. --Dryden. [1913 Webster] 2. Belonging to the natural or essential constitution; peculiar; not common; particular; as, every animal has his proper instincts and appetites. [1913 Webster] Those high and peculiar attributes . . . which constitute our proper humanity. --Coleridge. [1913 Webster] 3. Befitting one's nature, qualities, etc.; suitable in all respect; appropriate; right; fit; decent; as, water is the proper element for fish; a proper dress. [1913 Webster] The proper study of mankind is man. --Pope. [1913 Webster] In Athens all was pleasure, mirth, and play, All proper to the spring, and sprightly May. --Dryden. [1913 Webster] 4. Becoming in appearance; well formed; handsome. [Archaic] "Thou art a proper man." --Chaucer. [1913 Webster] Moses . . . was hid three months of his parents, because they saw he was a proper child. --Heb. xi. 23. [1913 Webster] 5. Pertaining to one of a species, but not common to the whole; not appellative; -- opposed to common; as, a proper name; Dublin is the proper name of a city. [1913 Webster] 6. Rightly so called; strictly considered; as, Greece proper; the garden proper. [1913 Webster] 7. (Her.) Represented in its natural color; -- said of any object used as a charge. [1913 Webster] In proper, individually; privately. [Obs.] --Jer. Taylor. Proper flower or Proper corolla (Bot.), one of the single florets, or corollets, in an aggregate or compound flower. Proper fraction (Arith.) a fraction in which the numerator is less than the denominator. Proper nectary (Bot.), a nectary separate from the petals and other parts of the flower. -- Proper noun (Gram.), a name belonging to an individual, by which it is distinguished from others of the same class; -- opposed to common noun; as, John, Boston, America. Proper perianth or Proper involucre (Bot.), that which incloses only a single flower. Proper receptacle (Bot.), a receptacle which supports only a single flower or fructification. [1913 Webster]WordNet (r) 3.0 (2006):

proper fraction n 1: a fraction with a numerator smaller than the denominator