police baton; truncheon; billy club
Refers specifically to the baton carried by police officers. The word is neutral and commonly used in news reports.
警官が警棒を手に取った。
The police officer picked up the baton.
デモ隊
They raised their batons toward the demonstrators.
extendable baton
Standard kanji spelling for a police baton.
Compound of 警 (けい, 'police') and 棒 (ぼう, 'stick, rod'). The exact historical derivation is uncertain, but the word is a straightforward modern compound.