Rich
Old English rīce ‘powerful, wealthy’, of Germanic origin, related to Dutch rijk and German reich ; ultimately from Celtic; reinforced in Middle English by Old French riche ‘rich, powerful’.
wiktionary
From Middle English riche(“strong, powerful, rich”), from Old English rīċe(“powerful, mighty, great, high-ranking, rich, wealthy, strong, potent”), from Proto-West Germanic *rīkī, from from Proto-Germanic *rīkijaz(“powerful, rich”), from Proto-Celtic *rīxs(“king”), from Proto-Indo-European *h₃reǵ-(“to straighten, direct, make right”).
Cognate with Scots rik(“mighty, great, noble, rich”), Saterland Frisian riek(“rich”), West Frisian ryk(“rich”), Dutch rijk(“rich”), German reich(“rich”), Danish rig(“rich”), Icelandic ríkur(“rich”), Norwegian and Swedish rik(“rich”). The Middle English word was reinforced by Old French riche, borrowed from the same Proto-Germanic root.
etymonline
rich (adj.)
Old English rice "strong, powerful; great, mighty; of high rank" (senses now obsolete), in later Old English "wealthy;" from Proto-Germanic *rikijaz (source also of Old Norse rikr, Swedish rik, Danish rig, Old Frisian rike "wealthy, mighty," Dutch rijk, Old High German rihhi "ruler, powerful, rich," German reich "rich," Gothic reiks "ruler, powerful, rich"), borrowed from a Celtic source akin to Gaulish *rix, Old Irish ri (genitive rig) "king," from Proto-Celtic *rix, from PIE root *reg- "move in a straight line," with derivatives meaning "to direct in a straight line," thus "to lead, rule" (compare rex).
The form of the word was influenced in Middle English by Old French riche "wealthy, magnificent, sumptuous," which is, with Spanish rico, Italian ricco, from Frankish *riki "powerful," or some other cognate Germanic word. Old English also had a noun, rice "rule, reign, power, might; authority; empire" (compare Reich). The evolution of the word reflects a connection between wealth and power in the ancient world, though the "power" sense seems to be the oldest.
In transferred and extended senses from c. 1200. The meaning "magnificent" is from c. 1200; that of "of great value or worth" is from mid-13c. Of food and colors, "having an abundance of a characteristic quality that pleases the senses," from early 14c.; of sounds, from 1590s; of soils from 1570s. Sense of "entertaining, amusing" is recorded from 1760. The noun meaning "the wealthy" was in Old English.
English once had a related verb rixle "have domination, rule," from Old English rixian "to rule."
