| frenum |
a membrane or fold of skin, such as that under the tongue, that controls or restrains the movement of a body part. |
| frenzy |
a seizure marked by violent agitation, excitement, or enthusiasm, or the activity accompanying such a seizure. [3 definitions] |
| frequence |
the state of being frequent. |
| frequency |
the fact of happening often or being frequent. [3 definitions] |
| frequency distribution |
a table of statistical data in which the observed values of a variable are grouped into classes, and the frequencies for each class are given. |
| frequency modulation |
see "FM." |
| frequent |
happening often or at close intervals. [3 definitions] |
| frequently |
numerous times; often. |
| frère |
(French) brother. [2 definitions] |
| fresco |
the art of painting on wet plaster with colors dissolved in water or limewater, or a picture produced by this method. [2 definitions] |
| fresh |
newly made, gained, or experienced. [11 definitions] |
| freshen |
to cause to be fresh; renew. [4 definitions] |
| freshen up |
to make oneself feel more comfortable or attractive, as by washing the face, combing the hair, or the like. |
| freshet |
a sudden rise or overflow of a stream, because of heavy rain or a sudden thaw. [2 definitions] |
| freshly |
newly or recently made or done. |
| freshman |
a first-year student at a high school, college, or university. [4 definitions] |
| freshwater |
consisting of or pertaining to water that is not salty. [3 definitions] |
| fresh water |
water that is not salty. |
| Fresnel lens |
a thin and relatively flat optical lens made of many stepped concentric rings, and having the properties of a thicker, more concave lens. |
| Fresnel mirrors |
two mirrors joined together at an angle slightly less than 180 degrees, so that a beam of light falling on them is reflected in different directions, producing interference fringes where the reflected light overlaps. |
| fret1 |
to feel or express worry, concern, or annoyance. [8 definitions] |