Druidic language

Druidic was the secret language of druids.

Sublanguages
Druidic was actually a language subgroup composed of two distinct but similar languages. The vast majority of druids spoke Drueidan; those from the Moonshaes spoke a language called Daelic.

History
Drueidan was developed by a powerful group of druids who worshiped Silvanus. Silvanus made an agreement with the other nature gods of the Faerûnian pantheon to allow druids all over Faerûn to speak it.

Daelic, on the other hand, was developed by druids who worshiped the Earthmother.