| flu |
influenza. |
| flub |
(informal) to do badly; botch; bungle. [2 definitions] |
| fluctuate |
to vary or change irregularly; rise and fall. [3 definitions] |
| fluctuation |
unsteadiness; vacillation. [2 definitions] |
| flue |
a duct, pipe, or other passage through which hot or cold air, smoke, or steam may be evacuated. |
| fluegelhorn |
a three-valved brass wind instrument that is similar to a cornet in pitch and appearance, but mellower in tone. |
| fluency |
the ability to speak or write smoothly and easily in another language. |
| fluent |
speaking or writing easily and smoothly. [4 definitions] |
| flue pipe |
an organ pipe in which sound is produced by a current of air that vibrates as it strikes the lip of an opening in the side of the pipe; flue. |
| fluff |
a soft, light, downlike substance, or a mass of such a substance. [7 definitions] |
| fluffy |
of, made of, or covered with fluff. [2 definitions] |
| fluid |
a substance, such as a liquid or gas, that can flow and that tends to conform to the shape of its container. [5 definitions] |
| fluid dram |
in the U.S., a unit of capacity equal to one eighth of a fluid ounce or 3.6966 milliliters. [2 definitions] |
| fluid ounce |
in the US, a unit of capacity equal to one sixteenth of a pint or 29.57 milliliters. [2 definitions] |
| fluke1 |
a triangular tip, as on an anchor or the head of a spear or arrow. [2 definitions] |
| fluke2 |
that which is accidentally successful; stroke of good luck. |
| fluke3 |
any of several flatfishes or flounderlike fishes. |
| fluky |
(informal) resulting from chance; accidental or lucky. [2 definitions] |
| flume |
a narrow gorge or ravine through which a stream flows. [3 definitions] |
| flummery |
any of several soft, thick, bland foods, such as boiled oatmeal or custard. [2 definitions] |
| flummox |
(informal) to confuse or puzzle. |