Definitions for "NGVD"
National Geodetic Vertical Datum. A measure of land elevation essentially the same as Mean Sea Level (MSL). NGVD is always given with the date of the datum.
National Geodetic Vertical Datum. National standard reference datum for elevations, formerly referred to as Mean Sea Level (MSL) of 1929. NGVD is used as the reference datum on most FIRMs.
See National Geodetic Vertical Datum (1929)