Yes, yen is a Scrabble word!
...and is worth 6 points in Scrabble, and 6 points in Words with Friends
yen
Verb
1. Have a desire for something or someone who is not present
Noun
1. A yearning for something or to do something
2. The basic unit of money in Japan; equal to 100 sen
What Scrabble words can I make with the letters in yen?
2 Letter Words