| Foureye butterflyfish | Chaetodon capistratus |
| fourfold | czworaki |
| fourhorn sculpin | kur rogacz |
| Fourier | Fourier |
| Fourier analysis | Analiza harmoniczna |
| Fourier number | Liczba Fouriera |
| Fourier series | Szereg Fouriera |
| Fourier transform | transformacja Fouriera |
| Fourier transform spectroscopy | Spektroskopia fourierowska |
| Fourqueux | Fourqueux |
| Fourspot butterflyfish | Chaetodon quadrimaculatus |
| fourteen | czternaście |
| Fourteen Holy Helpers | Czternastu Świętych Wspomożycieli |
| Fourteen Points | Czternaście punktów Wilsona |
| Fourteen Words | Fourteen Words |
| fourteen year old | czternastolatek |
| fourteen-year-old | czternastoletni |
| fourth | czwarty |
| Fourth Age | Czwarta Era |
| Fourth Battle of the Isonzo | Bitwy nad Isonzo |
| Fourth Council of Constantinople | Sobór Konstantynopolitański IV |
| Fourth Council of the Lateran | Sobór Laterański IV |
| Fourth Crusade | IV wyprawa krzyżowa |
| Fourth dynasty of Egypt | IV dynastia |
| Fourth generation computer | Komputer czwartej generacji |
| Fourth International | IV Międzynarodówka |
| Fourth Polish Republic | IV Rzeczpospolita |
| Fourth Republic | IV Republika Francuska |
| Fourth World | Czwarty Świat |
| Fouta Djallon | Futa Dżalon |
| fowl | drób |
| fox | laska |
| Fox Broadcasting Company | Fox Broadcasting Company |
| fox cub | lisię |
| Fox Islands | Wyspy Lisie |
| Fox Life | Fox Life |
| Fox Mulder | Fox Mulder |
| Fox River State Penitentiary | Więzienie Stanowe Fox River |
| Fox sisters | Siostry Fox |
| foxberry | borówka brusznica |
| foxglove | naparstnica |
| Foxit Reader | Foxit PDF Reader |
| foxtrot | fokstrot |
| Foza | Foza |
| Foča | Foča |
| Foča Region | Foča |
| FPGA | Field Programmable Gate Array |
| Fr | Frans |
| FR Fireball | Ryan FR Fireball |
| Fra Angelico | Fra Angelico |
| Fra Bartolomeo | Fra Bartolomeo |
| fractal | fraktal |
| Fractal compression | Kompresja fraktalna |
| fraction | ułamek |
| fractional expression | wyrażenie ułamkowe |
| Fractional Orbital Bombardment System | Metoda rażenia z orbity szczątkowej |
