- A very large vulture(Gymnogyps californianus), related to the condor of South America, found in the southern California mountains and nearly extinct. 加州秃鹰：一种很大的秃鹫（加利福尼亚神鹰 鹫属）， 与南美洲的秃鹰有亲缘关系，发现于加利福尼亚南部山区，现已几近灭绝
- four-way
- four-wheel
- four-wheel drive
- four-wheeler
- four–bagger
- four–color
- four–cycle
- four–dimensional
- four–eyed
- four–eyed fish
- four–flush
- four–footed
- four–in–hand
- four–leaf clover
- four–letter word
- four–o'clock
- four–poster
- four–star
- four–starred
- four–way
- four–wheel
- four–wheeled
- four–wheeler
- fout
- Fouta Djallon