Old Irish inherited the PIE root noun *doms ~ dm̥- ‘home’, which is reflected chiefly in the fixed locution [Verb of motion] dia daim ‘(go) to (one’s) home’. From the remnants of this ablauting, feminine root noun speakers created a somewhat anomalous i-stem, doim, doma. In addition Old Irish probably inherited a thematic masculine *domos continued mainly in the collocation dom/dam liac ‘house of stone, cathedral’, though the possibility of a Latin loan cannot be entirely excluded. A further trace of the root noun *dom- ~ *dm̥- is seen in déis ‘clientele’, which continues *dm̥-sth2i- ‘located in the house’. This proto-form, suggested by de Bernardo Stempel (NWÄI), has a close formal match in Lith. dimstis ‘courtyard’ and is reminiscent of Lat. domesticus ‘of the household’. This Latin form is shown to be of prehistoric origin despite its relatively late date of attestation. The possibility is explored that domesticus may be a remodeled reflex of the same compound inherited by Old Irish and Lithuanian, although domesticus may also be an inner-Latin formation.