simple past tense and past participle of dilute
"He diluted his coffee with water before adding sugar, making it much lighter in flavor."
In plain English: To dilute something means to make it weaker by adding more of another substance, usually water.
"The rain diluted the heavy smell in the air."
That has had something added in order to dilute it.
"The concentrated orange juice was diluted with water before serving."
In plain English: Diluted means something has been made weaker by mixing it with more of another substance, usually water.
"The watered-down juice tasted much weaker than I remembered."
Usage: Use "diluted" when referring specifically to the process of reducing concentration by adding a solvent, rather than using synonyms like "weakened" or "diminished," which imply loss of strength without necessarily involving an additive. Avoid confusing this adjective with the verb form in contexts where the subject itself is being reduced rather than mixed with another substance.