1) Hickory stick 2) Instrument of punishment 3) Item for Wackford Squeers 4) Old-school rapper 5) Rod of a kind 6) Stick of old school days 7) Switch 8) Switch iron and lead 9) Whip Found on https://www.crosswordclues.com/clue/ferule
Fer'ule noun [ Latin ferula : confer French férule . See Ferula .] A flat piece of wood, used for striking, children, esp. on the hand, in punishment. Found on http://www.encyclo.co.uk/webster/F/22
Fer'ule transitive verb [ imperfect & past participle Feruled ; present participle & verbal noun Feruling .] To punish with a ferule. Found on http://www.encyclo.co.uk/webster/F/22