frac·tion 
(frăkshən)
(frăkshən)n.
1. Mathematics An expression that indicates the quotient of two quantities, such as 1/3 .
2. A disconnected piece; a fragment.
3. A small part; a bit: moved a fraction of a step.
4. A chemical component separated by fractionation.
[Middle English fraccioun, a breaking, from Anglo-Norman, from Late Latin frāctiō, frāctiōn-, from Latin frāctus, past participle of frangere, to break; see bhreg- in the Appendix of Indo-European roots.]