Saraswati Maa other name

[shian]

Vanakkam,

The other name of Saraswati Maa is Saradha Devi
but i dont clear, acctualy is Saradha, Sardha or Saredhe...
Then i dont know the meaning of name Saradha ... why Saraswati Maa called Saradha ...

Please enlighten me about Saradha :)

Thank you