Full Idea
A simple way of approaching the modern notion of a predicate is this: given any sentence which contains a name, the result of dropping that name and leaving a gap in its place is a predicate. Very different from predicates in Aristotle and Kant.
Gist of Idea
A (modern) predicate is the result of leaving a gap for the name in a sentence
Source
David Bostock (Intermediate Logic [1997], 3.2)
Book Reference
Bostock,David: 'Intermediate Logic' [OUP 1997], p.74
A Reaction
This concept derives from Frege. To get to grips with contemporary philosophy you have to relearn all sorts of basic words like 'predicate' and 'object'.