Prognosticate, v. t. [imp. & p. p. Prognosticated; p. pr. & vb. n. Prognosticating.]
Etymology: [See Prognostic.]
To indicate as future; to foretell from signs or symptoms; to prophesy; to foreshow; to predict; as, to prognosticate evil. Burke. I neither will nor can prognosticate To the young gaping heir his father's fate. Dryden.
Syn. -- To foreshow; foretoken; betoken; forebode; presage; predict; prophesy.
Shades of meaning
Fernald has no entry of its own for prognosticate; he lists it under augur.
He lists it without comment; the entries above explain its neighbors.