This article argues that Irish Travellers' ideologies of languageness and their definition of Cant are closely linked to their perceptions of social reality. Cant is a communicative code which Travellers use beside English in Traveller-specific situations. Based on the analysis of focus groups, I take a folk-linguistic and anthropological approach and examine instances of metacommunication in which languageness and the status of Cant are negotiated among speakers, and explore what they suggest about the community and the local social setting. The analysis uncovers the criteria of 'ownership', 'activity', 'understanding' and 'privacy' as essential in the participants' definitions of languageness. I argue that these criteria are strongly linked to the community's understanding of themselves and relationships with Irish society. Further, I analyse speakers of different age groups' evaluations of Cant according to the above criteria, and show how what is considered as 'authentic' Cant is linked to life trajectories and perceptions of linguistic and social reality.