From Longman Dictionary of Contemporary Englishcodicilco‧di‧cil /ˈkəʊdəsɪl $ ˈkɑː-/ noun [countable] law 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)
Examples from the Corpus
codicil• At this juncture a codicil must be inserted.• Do not try to prepare a codicil without professional legal advice.• But with a telling codicil detailing in full what his compensation entitlement would be if he should happen to resign within six months.• In spite of the furor the codicil caused, life went on much as before.From Longman Business Dictionarycodicilco‧di‧cil /ˈkɒdəsɪlˈkɑː-/ noun [countable] LAW something that is added to a WILL (=document saying what will happen to someone’s money when they die) which makes changes to part of itShe specified in a codicil to her will that she wanted the house turned into an educational centre.Origin codicil (1400-1500) Latin codicillus, from codex; → CODEX 