- free exercise of Summer Special Olympics
- free expansion
- free extension
- free face
- free factor
- free fall
- free fall absolute gravimeter
- free-fall time
- free family
- free fatty acid
- free fatty acid,FFA
- free field
- freefield
- free field path
- free field sensitivity
- free-field sensitivity
- free flagellum
- free flight
- free floating macrophyte
- free flow ETC
- Free fluid
- free fluid index log
- free-flying telescope
- free-form curve
- free-form deformation