in grammar, a verb to which the nominative of any certain person cannot be prefixed; or, as others define it, a verb deponent of the two first and primary persons, as *deceit*, *apportet*, &c.

The impersonal verbs of the active voice end in *i*, and those of the passive in *tur*; they are conjugated through the third person singular of almost all the tenses and moods: they want the imperative, instead of which we use the present of the subjunctive; as *paniteat*, *pugnetur*, &c., nor, but a few excepted, are they to be met with in the supines, participles, or gerunds.

**IMPEVIOUS**, a thing not to be pervaded or passed through, either by reason of the closeness of its pores, or the particular configuration of its parts.