This word is acceptable for play in the UK dictionary that is being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. Collectively, the players known as backs, whose job it is to create and exploit space.

n. The imaginary tactical line across the field that passes through the backs, through their primary line of attack/defence (i.e. excluding any players in a more backward defensive position).

"D Paul Martin, the team's best player on the backline, is a potential free agent."