Old English wrað "angry" (literally "tormented, twisted"), from Proto-Germanic *wraith- (source also of Old Frisian wreth "evil," Old Saxon wred, Middle Dutch wret, Dutch wreed "cruel," Old High German reid, Old Norse reiðr "angry, offended"), from *wreit-, from PIE root *wer- (2) "to turn, bend." Rare or obsolete from early 16c. to mid-19c., but somewhat revived since, especially in dignified writing, or this:
Secretary: "The Dean is furious. He's waxing wroth."
Quincy Adams Wagstaf [Groucho]: "Is Roth out there too? Tell Roth to wax the Dean for a while."
Old English strengþu, strengð "bodily power, force, vigor, firmness, fortitude, manhood, violence, moral resistance," from Proto-Germanic *strangitho (source also of Old High German strengida "strength"), from PIE *strenk- "tight, narrow" (see string (n.)), with Proto-Germanic abstract noun suffix *-itho (see -th (2)). Compare length/long. From the same root as strong,