secret police 
noun [treated as plural]
A police force working in secret against a government’s political opponents.However, the new police lack any effective power against the Sandinista secret police or army....
- In places it was only Russian troops who protected the secret police from workers' anger.
- Ganev's career initially received a boost from his role as an official in the Stalinist secret police.
- substanceless
- substance P
- substand
- substandard
- substanding
- substant
- substantiability
- substantial
- substantial form
- substantialise
- substantialism
- substantialist
- substantiality
- substantialize
- substantially
- substantialness
- substantia nigra
- substantiate
- substantiation
- substantiative
- substantiator
- substantific
- substantify
- substantifying
- substantious