The term 'HEIST UNITS' can be broken down into two crossword solutions: GEES (4 letters) and HEIST (5 letters). GEES is an acronym for 'Gang Enforcement Emergency Services', which is a specialized unit of police officers that are trained to respond to high-risk situations such as bank robberies, hostage situations, and other criminal activities. HEIST is a term used to describe a robbery or theft, usually involving a large amount of money or valuable items.