admonish, commandment
警 centers on giving a firm warning or directive: admonishing someone to correct their behavior, or issuing a commandment that must be followed.
警 combines 敬 (respect, warn) with 言 (words), suggesting a verbal warning or admonishment. The exact historical development is well established as a phono-semantic compound.
The top part 敬 suggests a respectful but firm stance, and the bottom 言 is words. Picture someone speaking stern words to admonish or give a commandment.
For ケイ, imagine a police officer giving a stern warning: 'Okay, listen up!' The 'Kay' in 'Okay' cues ケイ, and the officer's words are the admonishment.
police
defense; defence; guard; policing; security
vigilance; caution; alertness; precaution; being on guard
warning; caution; admonition
police officer; policeman; constable
police officer; policeman; policewoman
warning; alarm; alert
prefectural police
Metropolitan Police Department (Tokyo)
police inspector
bodyguard; escort
assistant inspector
prefectural police (Osaka or Kyoto)
police superintendent
National Police Agency; NPA
city police; municipal police
policing (an area, etc.) by oneself; protecting by oneself; vigilantism
alarm bell; fire bell
Superintendent General of the Metropolitan Police
policewoman