Barbarous (adjective)

1. Savagely cruel or brutal.
2. Uncivilized or primitive.

Origin:

Late middle english: from old french barbareus, from latin barbarus 'foreign, uncivilized', of unknown origin.

Examples:

1. The conquerors inflicted barbarous acts upon the native population.
2. The dictator was notorious for his barbarous treatment of political prisoners.
3. The barbarous custom of foot-binding was once widespread in China.
4. The ancient city was sacked and its inhabitants subjected to barbarous violence.
5. The barbarous methods used for hunting and fishing have led to the depletion of many species.