Lewis & Short

bĕnĕfĭcĭārĭus, a, um, adj. [beneficium], pertaining to a favor.

  1. I. As adj. only once: res, Sen. Ep. 90, 2.
  2. II. Freq. subst.: bĕnĕfĭcĭārĭi, ōrum, m.; in milit. lang., soldiers who, through the favor of their commander, were exempt from menial offices (throwing up intrenchments, procuring wood and water, foraging, etc.), free or privileged soldiers: beneficiarii dicebantur milites, qui vacabant muneris beneficio; e contrario munifices vocabantur, qui non vacabant, sed munus reipublicae faciebant, Fest. p. 27; cf. Comm. p. 347: beneficiarii superiorum exercituum, Caes. B. C. 3, 88. Such beneficiarii were usually in attendance upon their commanders, and were promoted by them to office: Βενεφικιάλιοι οἱ ἐπὶ θεραπείᾳ τῶν Μαγιστράτων τεταγμένοι, Gloss.: beneficiarii ab eo appellati quod promoventur beneficio tribunorum, Veg. Mil. 2, 7; Caes. B. C. 1, 75; Plin. Ep. 10, 21 (32); 10, 27 (36); Inscr. Orell. 192; 929; 1394 et saep.