acme (n.) Look up acme at
"highest point," 1560s, from Greek akme "(highest) point, edge; peak of anything," hence "prime (of life, etc.), the best time," from PIE *ak-ma-, suffixed form of root *ak- "be sharp" (see acro-). In English it was written in Greek letters until c. 1620. The U.S. grocery store chain was founded 1891 in Philadelphia, Pennsylvania.