lackluster

形容词 lackluster:

1. lacking brilliance or vitality
   同义词：lacklustre, lusterless, lustreless
2. lacking luster or shine
   同义词：lacklustre, lusterless, lustreless

lack.lus.ter

adj.（形容词）
Lacking brightness, luster, or vitality; dull.See Synonyms at dull
暗淡的、无光泽的或缺乏活力的；不活跃的参见 dull