To study a flashcard deck by viewing the definition first as opposed to the term, you should notice a "Study Options" menu in the upper-left hand side of a flashcard deck in study mode. The options listed will be "Show Term First" and "Show Definition First". Click the box next to your preferred method and study away.

The process is roughly the same in the mobile app. In study mode you will notice an "Options" button in the upper-right hand corner of the flashcard. Click it and choose whether you would like "Term" or "Definition" to show first.