What is the meaning of Diluent?

That which dilutes.

A solvent or other liquid preparation used to dilute a sample prior to testing.

An agent used for effecting dilution of the blood; a weak drink.

Diluting; making thinner or weaker by admixture, especially of water.

third-person plural present indicative/subjunctive of diluer

third-person plural future active indicative of dīluō

Source: wiktionary.org