- A tiger(Panthera tigris subsp. tigris) of India, Bhutan, Bangladesh, and Myanmar. 孟加拉国虎：产于印度、不丹、孟加拉国和缅甸的老虎（孟加拉国 虎）
- four-eyed fish
- four eyes
- four flush
- four-flush
- four-footed
- fourgon
- fourgons
- fourhanded
- Four-H Club
- Four Horsemen of the Apocalypse
- Four Hundred
- Fourier
- Fourier analysis
- Fourierism
- Fourierisms
- Fourier series
- Fourier's theorem
- four-in-hand
- four-leaf clover
- four-letter word
- four-o'clock
- fourpenny nail
- fourplex
- fourplexes
- four-poster