潜せん入にゅう

noun, noun or participle which takes 'suru', intransitive verb

infiltration; sneaking in; going undercover

Used for secretly entering a place, often for investigation, espionage, or undercover operations. Commonly appears as 潜入する or 潜入捜査.

• 警けい察さつ官かんが組そ織しきに潜せん入にゅうして情じょう報ほうを集あつめた。

  A police officer infiltrated the organization and gathered information.