U-boat /ūˈbōt or (German) ooˈ/

A German submarine

• three deep
• three-dimensional
• three-dimensionality
• three estates
• three-farthing
• three-farthings
• threefold
• threefoldness
• threefoldnesses
• three-foot
• three-four
• three-four time
• three-halfpence
• three-halfpenny
• three-halfpennyworth
• three-halfpennyworths
• three-handed
• threeha'porth
• three-jaw chuck
• three-jaw chucks
• three kings of Cologne
• three-leafed
• three-leaved
• three-legged
• three-line whip