- A boat equipped to fight fires along waterfronts and on ships.救火艇，救火船：为扑灭沿水滨区和船上大火而装备起来的船
- ultrasonics
- ultrasonogram
- ultrasonograph
- ultrasonographies
- ultrasonography
- ultrasophisticated
- ultrasound
- ultrasound
- ultrastructure
- ultrathin
- ultraviolet
- ultraviolet
- ultraviolet astronomy
- ultraviolet dropout
- ultraviolet lamp
- ultravirus
- Ulugh Muztagh
- ululate
- ululated
- ululates
- ululating
- Ulyanovsk
- Ulysses
- um
- um