In general:

Wave will be generally understood in terms of signal. Waving for goodbye promises, that separation will not be forever.

Traditionally:

European
– Dreaming of wave: perform a good deed;
– Wave to beckons anyone: cautions to maintain their direction and calls to turn back;
– Wawing for goodbye: promises a reunion;
– Wave to welcome someone: announces a goodbye;
– Wave to make attention: on a chosen path you will not continue to go.

Hindu
– Dreaming of waving: you will make a journey;
– To see wave: you’ll have to be separated from loved ones.