COMMON If something is changed or reformed root and branch, it is changed or reformed completely, so that none of the old or traditional parts remain. These genuinely radical measures should change our economic system root and branch. Note: A root-and-branch reform, change or examination is a complete reform, change or examination. The Chief Inspector of Prisons called for root and branch reform of the prison system yesterday. The government has embarked on a root and branch review of the future of student finance. Note: In 1641 the Root and Branch Bill abolishing the government of the church by bishops was presented to the English Parliament. Those who supported the bill were known as `root-and-branch men', and the term has been used to refer to reform ever since.