di·lute / diˈloōt; dī-/ • v. [tr.] (often be diluted) make (a liquid) thinner or weaker by adding water or another solvent to it: bleach can be diluted with cold water. ∎  make (something) weaker in force, content, or value by modifying it or adding other elements to it: the reforms have been diluted. ∎  reduce the value of (a shareholding) by issuing more shares in a company without increasing the values of its assets.• adj. (of a liquid) made thinner or weaker by having had water or another solvent added to it. ∎  Chem. (of a solution) having a relatively low concentration of solute: a dilute solution of potassium permanganate. ∎  (of color or light) weak or low in concentration: a short measure of dilute sun.DERIVATIVES: di·lut·er n.

dilute XVI. f. dīlūt-, pp. stem of L. dīluere wash away, dissolve, f. DI- 1 + -luere, comb. form of lavāre wash, LAVE.
Hence dilution XVII.