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v. Present participle of lessen.

n. A growing lesser; reduction or decrease.

adj. becoming less in dimension or degree.

n. a change downward; a decrease; a reduction.

n. The act or process of making or becoming less. Specifically

n. In falconry, a soaring flight.

n. a change downward

"The amendment arose from a long-standing interest in lessening human exposure to mercury, a known neurotoxin and nephrotoxin."

alteration    modification    change   

attrition    sinking    dwindling    waning    shrinkage    shrinking    casualty    dwindling away   

decrease    drop-off    reduction   

lessen