(ˌ)fōˌlē(ˌ)äˈdə(r.), -də̄ noun
( plural folies à deux -ē(ˌ)(z)ä-)
Etymology: French, literally, double madness
: the presence of the same or similar delusional ideas in two persons closely associated with one another ; especially : the result of transmission of delusional ideas from one person to another