F

1. the sixth letter of the alphabet.
2. the fourth note of the diatonic scale of C major.

1. Fahrenheit.

   60°F

2. farad(s).
3. faraday(s).
4. (in racing results) favourite.

   2nd Miss Prism 2–1 F

5. female.
6. fighter (in designations of US aircraft types).

   the F117 Stealth fighter

7. filial generation.
8. fine (used in describing grades of pencil lead).

   an F pencil

9. (in motor racing) formula.

   an F1 driver

10. franc(s).

    $1.00 = F5.9645 as at April 29

11. France (international vehicle registration).
12. (in tables of sports results) goals or points for.

1. the chemical element fluorine.
2. force.

   F=ma

1. feminine.
2. (in units of measurement) femto- (10⁻¹⁵).

   the detection limits of the enzymatic activity tests are between 10 and 500 fg per test

3. (in textual references) folio.
4. forte.
5. (in racing results) furlong(s).

   2 m 3 f

6. denoting electrons and orbitals possessing three units of angular momentum.

   f-orbitals

1. focal length.

   apertures of f/5.6 to f/11

2. a function of a specified variable.

   the value of f(x)

3. frequency.

1. of or denoting a scale of temperature on which water freezes at 32° and boils at 212° under standard conditions.

   the temperature was steady at 65° Fahrenheit

mid 18th century: named after Gabriel Daniel Fahrenheit (1686–1736), German physicist.

noun, symbol

the SI unit of electrical capacitance, equal to the capacitance of a capacitor in which one coulomb of charge causes a potential difference of one volt.

mid 19th century: shortening of faraday. The term was originally proposed as a unit of electrical charge.

noun, symbol

a unit of electric charge equal to Faraday's constant.

early 20th century: coined in German from the name of Faraday, Michael.

noun, symbol

the chemical element of atomic number 9, a poisonous pale yellow gas of the halogen series. It is the most reactive of all the elements, causing very severe burns on contact with skin.

early 19th century: from fluor (see fluorspar) + -ine⁴.

1. the rate at which something occurs over a particular period of time or in a given sample.

   an increase in the frequency of accidents due to increased overtime

2. the rate per second of a vibration constituting a wave, either in a material (as in sound waves), or in an electromagnetic field (as in radio waves and light).

   different thicknesses of glass will absorb different frequencies of sound

mid 16th century (gradually superseding late Middle English frequence ; originally denoting a gathering of people): from Latin frequentia, from frequens, frequent- ‘crowded, frequent’.