Why is the ninth month called September?
1550s, from Latin dilutus, past participle of diluere "dissolve, wash away, dilute," from dis- "apart" + -luere, comb. form of lavere "to wash" (see lave). Related: Diluted; diluting. As an adjective from c.1600.
dilute di·lute (dī-lōōt', dĭ-)
v. di·lut·ed, di·lut·ing, di·lutes
To reduce a solution or mixture in concentration, quality, strength, or purity, as by adding water. adj.
Thinned or weakened by diluting.