pertaining to fractions; comprising a part or the parts of a unit; constituting a fraction:
comparatively small; inconsiderable or insignificant:
The profit on the deal was fractional.
Chemistry. of or noting a process, as distillation, crystallization, or oxidation, by which the component substances of a mixture are separated according to differences in certain of their properties, as boiling point, critical temperature, or solubility.
relating to, containing, or constituting one or more fractions
of or denoting a process in which components of a mixture are separated by exploiting differences in their physical properties, such as boiling points, solubility, etc: fractional distillation, fractional crystallization