Euro Acca simply means an accumulator which includes selections from the biggest leagues in European football. So instead of selecting a whole host of teams from English football for your accumulator you will instead choose selections from the Premier League, Serie A, La Liga and the Bundesliga. The Euro Acca will tend to include the biggest clubs in Europe (e.g. Real Madrid, Barcelona, Bayern Munich) and will therefore have a much greater chance of winning with those club being serial winners. It also means that you get get a bonus on your bets winnings, which you can read more about in the paragraph below.
What is an accumulator?
A win accumulator is a bet that contains 4 or more selections whereby every selection must win for the bet to be successful. The main advantage of a win accumulator is that the odds/winnings can be much higher, however with this comes greater risk. More and more bookies are now offering a refund on your bet if one team lets you down on any acca which contain 5 or more legs.