Lewis & Short

sējŭgae, ārum, v. 1. sejugis.

1. sējŭgis, is, m. (sc. currus) [sex-jugum], a team of six horses, a chariot drawn by six horses: (VICI) SEIVGE (EQVO), Inscr. Orell. 2593; 6179.
The same more freq. and class. in the plur.: sejuges aurati, Liv. 38, 35; so, sejuges, Plin. 34, 5, 10, § 19.
As adj.: sejuges currus, drawn by six horses, App. Flor. p. 356.
Collat. form sējŭgae, ārum, f. (in analogy with bigae, quadrigae, etc.), a chariot and six, Isid. Orig. 13, 36, 1 and 2.