资料来源 : pyDict

落后,跟不上

资料来源 : WordNet®

fall behind
     v 1: retreat [syn: {fall back}, {lose}, {drop off}, {recede}]
          [ant: {gain}]
     2: hang (back) or fall (behind) in movement, progress,
        development, etc. [syn: {lag}, {dawdle}, {fall back}]