A Big Leaguer is a professional baseball player who plays in one of the two major leagues, the American League (AL) or the National League (NL). The term 'Big Leaguer' is often used to refer to a player who has achieved success at the highest level of the sport. The crossword solutions for the term 'Big Leaguer' are PRO (3 letters) and ORIOLE (6 letters). PRO is an abbreviation for professional, which is the highest level of baseball. ORIOLE is the name of a team in the American League, the Baltimore Orioles.