(n.) 的大預言 having trouble making sense of this construct
的大预言

预言 means prophecy

大 means big

预言 here most likely is not plural - hence the whole 的大



edit: found this:

http://doraemon.wikia.com/wiki/Chapter_2:Prophecy_of_Doraemon

a chapter called "Prophecy of Doraemon" maybe it matches up to what you are reading...