form - func
- friction electrification
- friction fatigue
- friction feed
- friction loss
- friction tape
- friction weld
- friction wheel
- friction-feed
- frictional
- frictional electricity
- frictionless bearing
- fried
- Friedman's test
- Friele line element
- friend
- friend-foe recognition
- friend-or-foe
- friend-or-foe identification
- friendliness
- friendly user interface
