fierceness, fury
Finish is another word for completion starting with the letter F.
Fiesta
front
Frail.
flatten
fleet-footed
Flirting
The opposite for the word plain starting with letter f is FANCY.
Floccinaucinihilipilification is the longest word starting with F; it means the act of estimating something as worthless.
The 8-letter "f" word in science that means force is "friction."
One word for being late starting with the letter F is forgot.
"Pressure" is an 8-letter word related to force that starts with the letter "f."