An incestuous relationship is one involving sexual intercourse between two members of the same family, for example a father and daughter, or a brother and sister.
They accused her of an incestuous relationship with her father.
2. adjective
If you describe a group of people as incestuous, you disapprove of the fact that they are not interested in ideas or people from outside the group.
[disapproval]
Its inhabitants are a close and incestuous lot.
Hospitals are very incestuous places.
incestuous in British English
(ɪnˈsɛstjʊəs)
adjective
1.
relating to or involving incest
an incestuous union
2.
guilty of incest
3. obsolete
resulting from incest
an incestuous bastard
4.
resembling incest in excessive or claustrophobic intimacy
Derived forms
incestuously (inˈcestuously)
adverb
incestuousness (inˈcestuousness)
noun
incestuous in American English
(ɪnˈsɛstjuəs; ɪnˈsɛstʃuəs)
adjective
1.
guilty of incest
2.
of, or having the nature of, incest
3.
designating or characterized by a relationship of exceptional closeness or interrelation, often one regarded as unproductive, unseemly, etc.