diminish
     v 1: decrease in size, extent, or range; "The amount of homework
          decreased towards the end of the semester"; "The cabin
          pressure fell dramatically"; "her weight fall to under a
          hundred pounds"; "his voice fell to a whisper" [syn: {decrease},
           {lessen}, {fall}] [ant: {increase}]
     2: lessen the authority, dignity, or reputation of; "don't
        belittle your colleagues" [syn: {belittle}]
Source: WordNet® 2.0