Words related to Achilles
c. 1300, aue, "fear, terror, great reverence," earlier aghe, c. 1200, from a Scandinavian source, such as Old Norse agi "fright;" from Proto-Germanic *agiz- (source also of Old English ege "fear," Old High German agiso "fright, terror," Gothic agis "fear, anguish"), from PIE *agh-es- (source also of Greek akhos "pain, grief"), from root *agh- (1) "to be depressed, be afraid" (see ail). Current sense of "dread mixed with admiration or veneration" is due to biblical use with reference to the Supreme Being. To stand in awe (early 15c.) originally was simply to stand awe. Awe-inspiring is recorded from 1814.
Al engelond of him stod awe.
["The Lay of Havelok the Dane," c. 1300]
"back of the foot," Old English hela, from Proto-Germanic *hanhilon (source also of Old Norse hæll, Old Frisian hel, Dutch hiel), from PIE *kenk- (3) "heel, bend of the knee" (source also of Old English hoh "hock").
Meaning "back of a shoe or boot" is c. 1400. Down at heels (1732) refers to heels of boots or shoes worn down and the owner too poor to replace them. For Achilles' heel "only vulnerable spot" see Achilles. To fight with (one's) heels (fighten with heles) in Middle English meant "to run away."