Probabilist \Prob"a*bil*ist\, n. [Cf. F. probabiliste.]
[1913 Webster]
1. One who maintains that certainty is impossible, and that
probability alone is to govern our faith and actions.
[1913 Webster]
2. (Casuistry) One who maintains that a man may do that which
has a probability of being right, or which is inculcated
by teachers of authority, although other opinions may seem
to him still more probable.
[1913 Webster]