lighten
verb uk/ˈlaɪ.tən/ us/ˈlaɪ.t̬ən/
(BECOME BRIGHT)
[ I ]变浅，变淡
to become less dark
The sky had lightened and there were breaks in the clouds. 天空变亮了，云也渐渐散开了。
Opposite: darken
(MAKE LESS HEAVY)
lighten someone's burden, load, etc. 减轻（某人的）负担／压力（等等）
to make a difficult situation or responsibility easier
Getting a new assistant will lighten (= reduce) the workload considerably. 配备一名新助手会极大地减轻工作压力。
If elected, we will lighten the regulatory burden on small businesses.
College fees are high, but scholarships and grants can lighten the burden.
These measures do little to lighten the load of social workers.
If you could take care of the children today, that would help lighten my load.
(MAKE PALE)
[ T ]使变淡，使变浅
to make something lighter
The sun always lightens my hair. 在阳光下，我的头发颜色总是显得浅些。
(MAKE/BECOME LESS SERIOUS)
[ I or T ]（使）心情好转，（使）高兴起来
to (cause to) become happier and less worried
His mood lightened after the phone call. 他打完电话后情绪好了起来。
He tried to lighten the atmosphere by telling a joke. 他想通过讲笑话来缓解一下气氛。
Phrasal verbs
lighten something up 使…轻松活泼，使…不那么严肃
to make a speech or piece of writing less serious
I thought I'd slip in a few jokes to lighten up the talk. 我本想在讲话中加几个笑话来调剂一下气氛。
lighten up 放松，缓和
to become more relaxed and less serious
Oh, lighten up! I was only joking! 哦，别紧张！我只是在开玩笑！
I wish she'd just lighten up. 我希望她能放松一些。