Phantasma [noun]

They seemed like the Orama of the Greeks,—prophets while phantasma.

Claudius meanwhile pumped out the air-bubble of his soul, and thereafter, as a phantasma, ceased to be visible.

Between the acting of a dreadful thing / And 60 the first motion, all the interim is / Like a phantasma or a hideous dream.

Phantasma enim est sentiendi actus; neque differt a sensione, aliter quam fieri differt a factum esse.

The idea or phantasma, as he terms it, is the very perception or actus sentiendi.

Her ancient civility is gone, and her glory hath vanished as a phantasma.

Between the acting of a dreadful thing And the first motion, all the interim is Like a phantasma, or a hideous dream.

Shakespeare seems to use it ('phantasma') in this passage in the sense of nightmare, which it bears in Italian.