fain

形容词 fain:

1. having made preparations
   同义词：disposed, inclined, prepared

副词 fain:

1. in a willing manner
   同义词：gladly, lief

1. I would fain help you.
   我乐意帮助你。
2. Men and birds are fain of climbing high.
   不论人还是鸟都愿意往高处攀。
3. I would fain go with you.
   我高兴和你一起去。

fain

adv.（副词）
Happily; gladly:
幸福地；乐意地：
例句：
.I would fain improve every opportunity to wonder and worship, as a sunflower welcomes the light.(Henry David Thoreau)
.我将像向日葵迎接太阳那样乐意在每一个机会赞美和崇拜（它）.(亨利·戴维·梭罗)

Archaic Preferably; rather.
【古语】 宁愿；宁可
adj.Archaic （形容词）【古语】
Ready; willing.
愿意的；乐意的
Pleased; happy.
高兴的；幸福的
Obliged or required.
被迫的，要求的

来源：
Middle English
中古英语
from Old English fôgen [joyful, glad]
源自 古英语 fôgen [高兴的，快乐的]