'Dilution' definitions:

Definition of 'dilution'

From: WordNet
noun
A diluted solution
noun
Weakening (reducing the concentration) by the addition of water or a thinner [ant: concentration]

Definition of 'Dilution'

From: GCIDE
  • Dilution \Di*lu"tion\, n. [Cf. F. dilution.] The act of diluting, or the state of being diluted. --Arbuthnot. [1913 Webster]