Lewis & Short

dū̆plĭcārĭus, ii, m. [duplex], a soldier who receives double pay as a reward, Varr. L. L. 5, § 90 Müll.; Liv. 2, 59 fin.; Inscr. Orell. 3533; 4994 (cf. Caes. B. C. 3, 53 fin.; Liv. 7, 37; and 24, 47); also written DUPLICIARIUS, Inscr. Orell. 3534; see also duplaris.