Question

Fain mostly likely means

Answer 1

1 archaic :  happy, pleased
2 archaic :  inclined, desirous
3 a : willing
he was very fain, for the young widow was “altogether fair and lovely … ” — Amy Kelly
b :  being obliged or constrained :  compelled
Great Britain was fain to devote its whole energy … to the business of slaying and being slain — G. M. Trevelyan

Answer 2

Hey there!

The word "fain" means willing to or obliged under certain circumstances. An example sentence might be: 

"He was fain to do the thing his friend asked since he knew he would be compensated for it."

If you have single word answers, choose the answer that is most like "willing" or "obliged."

Hope this helped you out! :-)