Green’s Dictionary of Slang

(W.I., Bdos) to whisper together.

1976		Barbados Herald 22 June n.p.: It has another meaning when the Big Four get together and ‘whizzy-wizzy’ at ‘So-and-So’s’ house in Trinidad.
1996		Allsopp Dict. Carib. Eng. Usage 608/2: wizzy wizzy (whizzy-whizzy) [...] To whisper; to speak in huddled secrecy.