in terrorem /in te-rōˈrem or -röˈ/

As a warning

• four-packs
• four-part
• four-parted
• fourpence
• fourpences
• fourpennies
• fourpenny
• fourpenny one
• four-poster
• four-posters
• four-pounder
• four-pounders
• fours
• fourscore
• fourscorth
• four-seater
• four-seaters
• fourses
• foursome
• foursomes
• four-square
• four-stroke cycle
• fourteen
• fourteener
• fourteeners