Full Idea
Stoics place predicates among the incomplete 'lekta'.
Clarification
'Lekta' are things said
Gist of Idea
Predicates are incomplete 'lekta'
Source
report of Stoic school (fragments/reports [c.200 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.63
Book Reference
'The Stoics Reader', ed/tr. Inwood,B/Gerson,L.P. [Hackett 2008], p.16
A Reaction
This seems to be the modern Fregean logician's concept of a predicate.