The term “cause” is ubiquitous in life and science. It is surprising how, generally speaking, the existing all-purpose dictionaries, and even «professional» ones, are clumsy in their attempts to define “cause” and its derivative terms. We urgently need a more satisfactory definition of these words, along the following lines: an acting of object x on object y is the cause of the change in object y, when at the same time object x acts on object y, object y changes, and if something of the type of object x acts on an object of the type of object y, then object y changes. When expanding the proposed definition, I consider, among others: (a) traditional counterarguments aimed at the existence of cause-effect relation, (b) the question of necessity as a component of the notion of causality, (c) the notion of acting on something and the circumstances of its occurrence, (d) the essence of change, and (e) the causality principle. In addition, I sketch the relation of the reconstructed notion of causality to the notions of motivation, perpetration, and the act of creation (in arts and in Catholicism).