\In"cu*bus\, n.; pl. E. {Incubuses}, L. {Incubi}. [L.,
the nightmare. Cf. {Incubate}.]
1. A demon; a fiend; a lascivious spirit, supposed to have
   sexual intercourse with women by night. --Tylor.

         The devils who appeared in the female form were
         generally called succubi; those who appeared like
         men incubi, though this distinction was not always
         preserved.                            --Lecky.

2. (Med.) The nightmare. See {Nightmare}.

         Such as are troubled with incubus, or witch-ridden,
         as we call it.                        --Burton.

3. Any oppressive encumbrance or burden; anything that
   prevents the free use of the faculties.

         Debt and usury is the incubus which weighs most
         heavily on the agricultural resources of Turkey.
                                               --J. L.
                                               Farley.