Refers to the location where someone (often a fugitive or person in hiding) is staying concealed. Commonly used in news reports about criminals or missing persons.
The police tracked down the criminal's hideout.
His hiding place is still unknown.
Compound of 潜伏 (せんぷく, 'hiding, lying low') and 先 (さき, 'destination, place'). The reading さき is a standard kun'yomi for 先 when used as a suffix indicating a location.