An Etymological Dictionary of the German Language/frohn
frohn, adj., ‘lordly, holy,’ now only preserved as the first component in archaic compounds; from MidHG. vrôn, adj., ‘relating to the master or lord, sacred.’ In OHG. there appears instead of an adj. *frôn a petrified form frôno, ‘magnificent, divine, sacred,’ which is prop. a gen. plur. of frô, ‘lord’ (used only in the vocative). In MidHG. vrôn appears in numerous compounds for the temporal lord, as well as for the κύριος, ‘the lord,’ κατ’ ἐξοχήν, ‘Christ’; comp. MidHG. vrônlîchnam, m., ‘Christ’s body, the host,’ ModHG. Frohnleihnam; MidHG. vrônkriuze, OHG. daz frôno chrûzi, ‘the cross of Christ’; MidHG. vrônalter, ‘high altar,’ &c.; also vrônhof, ‘mansion,’ vrônwalt, ‘a wood belonging to the lord,’ vrônrëht, ‘public right.’ ModHG. retained Frohndienst, from MidHG. vrôndienst; see fröhnen. As to OHG. frô,‘O lord,’ stress must be laid on its correspondence to AS. freá, ‘lord,’ as well as OSax. frao. Goth. has a form with j, frauja, m. (AS. frêgea), ‘lord,’ which is seen in HG. in the fem. forms OHG. frouwa, MidHG. vrouwe, Goth. *fraujô, With these some connect in Scand. the names of the deities Freyr and Freyja. Whether the stem fraun-, for frawun- and fraujan-, in the sense of ‘gracious, friendly,’ is allied to the adj. froh, ‘glad,’ remains to be proved. Comp. Frau.
frohn, OHG. frô and Goth. frauja, 'lord,' are cognate with Sans. pûrva, pûrvya, and OSlov. prǔvǔ, 'first' (OHG. frô, from frawan, equiv. to pṛwo-, Goth. frauja, from frawjan, equiv. to pṛwyo; Sans. pûrvya, as an attribute of the gods, corresponds to OIc. Freyr (comp. Gott).