birch rod; switch
A bundle of twigs or a single branch used for corporal punishment, historically associated with discipline in schools or households.
In old schools, you could be hit with a birch rod if you did something bad.
Standard kanji spelling; 枝 (branch) + 鞭 (whip).
Mixed kanji-kana spelling, sometimes used for readability.
Compound of 枝 (eda, 'branch') and 鞭 (muchi, 'whip'). The exact historical derivation is uncertain, but the word transparently describes a whip made from a branch.