Definition of Mare Nostrum in US English:

Mare Nostrum

(also mare nostrum)


  • The Mediterranean Sea, regarded as the territory of or under the control of the European Mediterranean countries, especially Italy (originally so called by the Romans). Hence: any sea or other stretch of water belonging to or under the control of a nation.


1920s. From classical Latin mare nostrum, lit. ‘our sea’ from mare sea + nostrum, neuter singular of noster our.