pa·ter·fa·mil·i·as (pā'tər-fə-mĭl'ē-əs, pä'-, pāt'ər-) n.
pl.pa·tres·fa·mil·i·as (pā'trēz-, pä'-, pāt'rēz-) A man who is the head of a household or the father of a family.
[Latin paterfamiliās : pater, father; see pater + familiās, archaic genitive of familia, family; see family.]