PA,
Equivalent airspeed means the calibrated airspeed of an aircraft corrected for adiabatic compressible flow for the particular altitude. Equivalent airspeed is equal to calibrated airspeed in standard atmosphere at sea level.
Emphasis added.
Do you mean
uncorrected? The calibration law for CAS does take account of compressibility. EAS doesn't - it has nothing to do with compressibility. The Bernoulli equation for dynamic pressure,
q = ½ ρ V², is an
incompressible solution to Euler's equation. This is still true even if
ρ V² is swapped for
γ p M².
Calibration law is in NACA
Report 837 (Aiken, W. 1946. Langley.)