Definition of "agential"

Becoming more aware of the progress that scientists have made on behavioral fronts can reduce the risk that other natural scientists will resort to mystical agential accounts when they exceed the limits of their own disciplinary training.

2012 January, Stephen Ledoux, “Behaviorism at 100”, in American Scientist‎, volume 100, number 1, United States: Sigma Xi, page 60

Even if the suffix be formally identical with the agential suffix, it has not the same function.

1918, Henry Bradley, A New English Dictionary on Historical Principles, volume IX, page 922, column 2

Semantically, a majority of agentials refer to avian vocalization. Examples are: screamer, whistler, warbler, trumpeter, and the suffixless chat.

1986, Geolinguistics, page 19