co ‧ di ‧ cil /ˈkəʊdəsɪl, ˈkəʊdɪsɪl $ ˈkɑː-/ BrE AmE noun [countable] law
[ Date: 1400-1500 ; Language: Latin ; Origin: codicillus , from codex ; ⇨ ↑ codex ]
a document making a change or addition to a ↑ will (=a legal document saying who you want your money and property to go to when you die)