The Tamiḻ-Brāhmī or Tamiḻi inscriptions are the earliest available written records in Tamil and the Dravidian family of languages. These records constitute a unique opportunity to better understand the structure of Early Old Tamil or Pre-Sangam Tamil and Proto-Dravidian. The language of Tamiḻi inscriptions has been examined by early and contemporary scholars (Mahadevan 2003, 2014; Meenakshisundaran 1965; Mahalingam 1974; Panneerselvam 1972; Pillai 1956; Pilot-Raichoor 2012; Zvelebil 1964). The language of both Tamiḻi inscriptions and that of Sangam literature constitute corpus languages (Kruschwitz 2015) as no native speaker of these corpora is available today. This type of ‘corpus language’ presents complex linguistic configurations not readily discernible when compared to its contemporary counterparts. Any attempt to exhaustively summarize the linguistic structure of the Tamiḻi corpus within the limits of this paper would result in inevitable lacunae and theoretical misunderstanding. The object of this study is to propose a descriptive analysis of a single Tamiḻi inscription, Pulimāṉkōmpai-3 (hereafter PK3), within the framework of historical and comparative linguistics. This is an attempt to show how historical and comparative linguistics methods might help to understand the Early Old Tamil epigraphical data and to shed some new light on the reconstruction of Proto-Dravidian.