dilute solution

Solution in which the sum of amount fractions of all the solutes is small compared to 1.
Source:
Physical Chemistry Division, unpublished
PAC, 1994, 66, 533 (Standard quantities in chemical thermodynamics. Fugacities, activities and equilibrium constants for pure and mixed phases (IUPAC Recommendations 1994)) on page 535
See also:
Purple Book, p. 57