Worrying has never been properly studied. It is difficult to induce and to measure and has never been clearly defined. Some view it as neurotic behaviour synonymous with anxiety, whereas others indicate the positive aspects of the ‘work of worrying’. Seen mainly as a cognitive process, worrying is defined as a process of gradual involvement with external threat due to its relevance to some anxiety‐inducing content. It is proposed that' incubation of threat' is a central feature of worrying. A specially devised methodology has been used in an attempt to validate empirically some of these notions. The process of involvement which results in viewing a threat with growing apprehension has been demonstrated through vicarious worrying. Certain psychodynamic implications of the definition and of the findings are discussed.