This achievement requires that you finish an entire crossword in under 5 minutes. This will probably come naturally while going for "The W-Team" achievement. There are two ways to attempt to go for this. The first one involves just completing a puzzle naturally which has a lot of players in it. If there are 4+ players completing a puzzle from the start, there should be no trouble finishing it in less than 5 minutes. The other method involves going solo. First complete a puzzle to just before completion and then take a picture of the board. Then start up the same puzzle again and fill it out as fast as you can using the picture you just took. Be quick and this achievement can be yours.