細馬 [细马]

Jyutping sai3 maa5
Pinyin xì mǎ

Definitions (CC-CANTO)
  1. police patrol [colloquial]
Definitions (粵典–words.hk)
  1. 名詞、術語、香港
    屬​於​警區​，​而​唔​係​總區​交通部​嘅​警察​電單車​；​同​交通部​嘅​大​馬​相比​，​車身​比​較細​，​通常​負責​係​區內​巡邏
    police patrol motorcycle; literally: small horse