the.com/genuine
The thing itself, not its very convincing understudy.
means Authentic, real, and exactly what it claims to be — no imitation, no pretense.
from From Latin genuinus, innate or natural — possibly tied to genu (knee), recalling a Roman father placing a newborn on his knee to claim it as truly his.
Knee theoryMay trace to fathers acknowledging children by knee.
Engine cousinShares a root with genius, generate, and genus.
Real testThe word itself is hardest to fake convincingly.