Definition of "syntactically"

Thus, there is a third kind of judgment, which we shall call characterization. The wa-phrase and ga-phrase serve syntactically to distinguish predicational judgment not only from nonpredicational description but also from characterizational judgment.

1965 June 4, Shigeyuki Kuroda, “Generative grammatical studies in the Japanese language”, in DSpace@MIT‎, retrieved 2014-02-24