balkline
noun
balk·line ˈbȯ-ˌklīn 
1
: a line across a billiard table near one end behind which the cue balls are placed in making opening shots
2
a
: one of four lines parallel to the cushions of a billiard table dividing it into nine compartments
b
: a billiards game that sets restrictions in scoring caroms according to these lines
Example Sentences
Recent Examples on the Web The main carom billiards games are straight rail, balkline and especially three cushion billiards. 
John Torsiello, courant.com, 13 Nov. 2019
John Torsiello, courant.com, 13 Nov. 2019 Word History
First Known Use
1839, in the meaning defined at sense 1