What is "ducato"

Ducato can refer to:

• the Italian word for a duchy, derived from the Latin ducatus
• the former coin ducat, called after the dogal (i.e. 'ducal') state of Venice
• a family name, and things named after its members, notably Danielducato after the Italian (Sardinian) amateur astronomer Daniela Ducato
• the van model Fiat Ducato
• the Military Sealift Command ship MV Cape Ducato =? USS Cape Ducato