用法:
1 [I] become less 变少:
The pain was already lessening. 疼痛正在减轻.

用法:
2 [Tn] reduce (sth) 减少（某事物）:
lessen the impact, likelihood, risk of sth 减少某事物的影响、 可能性、 冒险性.

• unbowed
• unbreakable
• unbridled
• unbroken
• unbuckle
• unburden
• unbusinesslike
• unbutton
• unbuttoned
• uncalled-for
• uncannily
• uncanny
• uncared-for
• unceasing
• unceasingly
• unceremonious
• unceremoniously
• uncertain
• uncertainly
• uncertainty
• uncharitable
• uncharitably
• uncharted
• unchecked
• unchristian