资料来源 : Webster's Revised Unabridged Dictionary (1913)

Lessen \Less"en\ (l[e^]s"'n), v. t. [imp. & p. p. {Lessened}
   (-'nd); p. pr. & vb. n. {Lessening}.] [From {Less}, a.]
   To make less; to reduce; to make smaller, or fewer; to
   diminish; to lower; to degrade; as, to lessen a kingdom, or a
   population; to lessen speed, rank, fortune.

         Charity . . . shall lessen his punishment. --Calamy.

         St. Paul chose to magnify his office when ill men
         conspired to lessen it.                  --Atterbury.

   Syn: To diminish; reduce; abate; decrease; lower; impair;
        weaken; degrade.

资料来源 : WordNet®

lessening
     n : a change downward; "there was a decrease in his temperature
         as the fever subsided"; "there was a sharp drop-off in
         sales" [syn: {decrease}, {drop-off}] [ant: {increase}]