The late Ottoman and early Turkish Republican projects of modernity need to be examined as a conversation and translation among numerous Ottoman intellectuals, scholars, bureaucrats, deputies, political leaders as well between them and their counterparts in the West and other Muslim domains. In this frame, this paper focuses on the conceptions of religion and secular in the Ottoman periodical press as dialogue and contestation among multiple socio-political actors. Despite the high number of studies on Turkish secularization, there is no systematic study of the terms used for secular in Ottoman and Turkish intellectual and political domains. This paper undertakes a genealogical mapping of the expressions used for secular in Ottoman periodicals in early twentieth century. By undertaking a key word search in Ottoman periodical publications through two online databases, which are those of the ISAM library and Islamic Journals Project, and reading the relevant articles, and then broadening the research based on emerging new key words, the paper argues that the following terms were used for the secular: ladini, ladinilik, laique, laiklik. The expressions gayr-? dini (not religious) and dinsizlik (irreligion) were also used. The paper presents particularly the periods roughly around which these terms were coined or received a wider circulation as well as pinpoints the different meanings they were assigned. In the pursuit of a linguistic labelling of the terms standing for the secular, the paper also shares the insights of the critical scholarship on the categories of religion and secular. The arguments of W. C. Smith, T. Asad, A. Tayob, among others, are paid attention in examining religion and secular in the Ottoman/Turkish context. In this respect, the paper studies the ways in which religion (din) was defined in Ottoman periodicals, particularly as an abstract and universal category of belief, elaborated vis-à-vis the construction of its opponent dinsizlik (irreligion). By examining essays in different Ottoman Turkish periodicals, between 1908 and 1925, the paper examines the linguistic and historical coining and redefinition of lexicon for religion and secular, whereby words are not mere words but constructions-in-formation, shaped by their social, legal, and political milieus, attesting the contested and shared conversations among different social actors.