The Collaborative International Dictionary of English v.0.48:

Chelidonic \Chel`i*don"ic\, a. [See Celandine.] (Chem.)
   Of, pertaining to, or derived from, the celandine.
   [1913 Webster]

   Chelidonic acid, a weak acid extracted from the celandine
      (Chelidonium majus), as a white crystalline substance.
      [1913 Webster]