Risk with unknown probability distribution of the outcomes
A sure outcome is just a special case of a risky alternative with a degenerate probability distribution.
Under a set of appropriate conditions, the choice of a sure outcome over an ambiguous alternative can be attributed ambiguity aversion. But since different authors define ambiguity aversion somewhat differently, the &quot;appropriate conditions&quot; also differ. On the other hand, choosing a sure \$100 over an uncertain distribution over \$1 and \$2 can hardly be called ambiguity averse.