Ambiguity (Uncertainty) Aversion

Definition 1

Ambiguity aversion, or uncertainty aversion, is the tendency to favor the known over the unknown, including known risks over unknown risks. For example, when choosing between two bets, we are more likely to choose the bet for which we know the odds, even if the odds are poor, than the one for which we don’t know the odds.

Source: Behavioral Economics

Definition 2