Of or pertaining to actuaries. / Relating to statistical calculation, especially pertaining to insurance.

By actuarial principles. / In a manner performed by an actuary. / From an actuarial perspective.

(dated) Registrar, clerk. [16th-19th c.] / A professional who calculates financial values associated with uncertain events subject to risk, such as insurance premiums or pension contributions.

plural of actuary

(applied mathematics, insurance, finance) The discipline within applied mathematics dealing with risk assessment and the modelling of uncertainty; the rigorous application of mathematical and statistical methods to assess risk, in industries including insurance and finance.