The crossword solution for the term 'Billiards Concern' is ANGLE, which is a five-letter word. ANGLE is an important concept in billiards, as it refers to the direction of the cue ball after it has been struck by the cue stick. The ANGLE of the cue ball determines the trajectory of the ball and how it will interact with other balls on the table. It is important for players to understand angles in order to make successful shots.