Ian, G3SEK wrote:
"The IEEE Dictionary mavens have produced a very HF-cebtric definition
of "ground wave"."

Regretable. Seems clear that a ground wave would require interaction
with the ground. According to Terman it does. On page 803 of his 1955
edition, Terman says:

"The "ground wave" (also sometimes called surface wave) can exist when
the transmitting and receiving antennas are close to the surface of the
earth and are vertically polarized. This wave, supported at its lower
edge by the presence of the ground, is of practical importance at
broadcast and lower frequencies."

The ground wave requires the earth to participate in its propagation and
the earth gives the ground wave a continuation beyond the line-of-sight
without atmospheric or ionospheric intervention.

Best regards, Richard Harrison, KB5WZI