to make (a liquid) thinner or weaker by the addition of water or the like.

to make fainter, as a color.

to reduce the strength, force, or efficiency of by admixture.

to become diluted.

reduced in strength, as a chemical by admixture; weak

a dilute solution.

verb

concentrate , strengthen , thicken

verb

adulterate , alter , attenuate , cook , cut , decrease , deliquesce , diffuse , diminish , doctor * , doctor up , irrigate , lace , lessen , liquefy , mitigate , mix , moderate , modify , needle * , phony up , plant , qualify , reduce , shave * , spike , temper , water , water down , thin , weaken

adjective

thin , washy , watered-down , waterish , watery , weak