Orkish
From Tolkien Gateway
Orkish was a general term for the jumble of languages used by the Orcs, composed from corrupted borrowings from other languages of Middle-earth. The variations in Orkish between different tribes and types of Orc were so great that it was often useless for communication, and so a standard language was necessary. Sauron devised his Black Speech for this purpose in Mordor, but in practice the Common Tongue was more normally used.