gilarion wrote:

F is the sixth letter of the Latin alphabet.

However 'F' can also mean

Fahrenheit
Farad, a unit for electric capacitance
Faraday constant
Fluorine
Focal length of a lens
f-number (sometimes called f-ratio, f-stop, or written f/), the focal length divided by the aperture diameter
Force
Form (botany)
Frequency
Bioavailability, which is expressed as the letter "F" in medical chemistry equations
F band, the range of radio frequencies from 3 to 4 GHz
f-block, a group of elements on the periodic table elements
F region, part of the ionosphere
Haplogroup F (Y-DNA), a patrilineal haplogroup
Haplogroup F (mtDNA), a matrilineal haplogroup
Phenylalanine, abbreviated as Phe or F
Helmholtz Free Energy, also abbreviated as A
The electromagnetic field tensor in electromagnetism
This is often generalize to include the field tensors of other interactions, as in i.e. the gluon field strength tensor.

IN EBAY TERMS THOUGH IT MEANS F**K ALL

or it could mean fellatio