intercolumnium

inter-cŏlumnĭum, i, n. [columna],

the space between two columns , intercolumniation : ambulationis, Cic. Q. Fr. 3, 1, 2, § 5: signa omnibus intercolumniis disposita, id. Verr. 2, 1, 19; Vitr. 3, 1; 4, 3; Vulg. 1 Reg. 7, 31.