'Codicil' definitions:

Definition of 'codicil'

From: WordNet
noun
A supplement to a will; a testamentary instrument intended to alter an already executed will

Definition of 'Codicil'

From: GCIDE
  • Codicil \Cod"i*cil\, n. [L. codicillus, dim. of codex: cf. F. codicille. See Code.] (Law) A clause added to a will. [1913 Webster]