A vagina of extraordinarily wide caliber (diameter), usually demonstrating a canal depth that is just as impressive in magnitude (>7 inches). The labia minora and labia majora are usually spaced far apart, and the vaginal orifice, as seen externally while looking at the vulva, appears to be a round hole. During intercourse, a macrovagina can give the false impression that a penis is very small. Macrovagina is often demonstrated by putting large objects inside, such as fists, cans, or Louisville sluggers.
My penis is not small; she just said she didn't feel it inside because she has a macrovagina.