Webster's Revised Unabridged Dictionary · 1913

Casuist

Casuist , noun

[Latin casus fall, case; compare French casuiste. See Casual.]

One who is skilled in, or given to, casuistry.
The judment of any casuist or learned divine concerning the state of a man's soul, is not sufficient to give him confidence. — South

Casuist , intransitive verb

To play the casuist. — Milton