peh₂-tér-
“one who protects, father”patron, patriot, patrimony, pattern
Extended form of *ph₂tḗr giving Latin patrōnus, English patron, patriot, patrimony, pattern.
Discussion
The PIE form *peh₂-tér- (one who protects, father) is an agent noun from the root *peh₂- (to protect, to feed, to shepherd), formed with the kinship suffix *-tér- that marks familial agents. The father is, etymologically, "the protector" — not the begetter but the guardian.
The cognate set is one of the most famous in comparative linguistics: Latin pater, Greek patḗr, Sanskrit pitár-, Gothic fadar, Old Irish athir, Armenian hayr — all continuing *ph₂tḗr with regular branch-specific sound changes. The word is so perfectly preserved across every branch that it serves as the standard demonstration of IE sound correspondences in introductory textbooks.
Latin pater generated: paternal, patriarch (patḗr + arkhḗ, father-rule), patrimony (father-wealth), patron (one who acts as a father-protector), pattern (from patron — the master-copy that guides production), and the word pope (from Greek pápas, an informal "father" title). The country name patria (fatherland) gave English patriot, expatriate, and repatriate.
The Jupiter connection is paramount: Latin Iūpiter contracts *Dyeu-ph₂tér ("Sky-Father"), combining the PIE sky-word with the PIE father-word into the name of the supreme Roman deity. Sanskrit Dyáuṣ Pitā is the exact structural match — the same compound, the same meaning, preserved independently in two branches separated by three thousand miles.
English father (OE fæder, from PGmc *fadēr) continues the root natively with Grimm's Law: PIE *p > PGmc *f. German Vater shows the High German shift from *f to v.