Definitions:

1. A Scottish and Irish surname, often linked to the Hatfield-Mccoy feud, a famous 19th-century family rivalry in the U.S. NOUN
   • The legend of Elijah McCoy is often cited as the origin of the phrase "The Real McCoy".
2. Term most commonly associated with the phrase "The Real McCoy", which means something genuine, authentic, ot the original version of something. NOUN
   • After trying multiple brands, I finally found the real McCoy when it comes to quality leather shoes.

Synonyms:

• authentic
• bona fide
• legit
• original
• the genuine article