The thick, creamy sauce that slurps out of a bird when she is aroused (very nice on a piece of apple pie).
"After dinner I enjoyed my aunt's cherry pie with a thick helping of bird's custard"
by Bob Sometimes March 23, 2005
1 more definition
A thickish, yellowish discharge emitted from a ladies clunge when she is particularly receptive to sir's amorous advances. The favoured dish when dining at the Y
When eating hairy pie I do like a helping of bird's custard.
by zippy_uk December 23, 2006