We don't have synonyms for predeclare yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are preclare and predecease.
(v) :
(transitive) To declare or announce beforehand.
(v) :
(transitive, programming) To declare some source code element (such as a class) in advance of its full description, so that other preceding parts of the code can refer to it.
(v) :
(transitive) To declare or announce beforehand.
(v) :
(transitive, programming) To declare some source code element (such as a class) in advance of its full description, so that other preceding parts of the code can refer to it.