n. [ L. auctarium. ] That which is superadded; augmentation. [ Obs. ] Baxter. [ 1913 Webster ]

n.; pl. Actuaries [ L. actuarius copyist, clerk, fr. actus, p. p. of agere to do, act. ] 1. (Law) A registrar or clerk; -- used originally in courts of civil law jurisdiction, but in Europe used for a clerk or registrar generally. [ 1913 Webster ]

2. The computing official of an insurance company; one whose profession it is to calculate for insurance companies the risks and premiums for life, fire, and other insurances. [ 1913 Webster ]