frenulum |
one of a group of stiff projections on the hind wing of some moths that join with a structure on the front wing to fasten the wings together in flight. |
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. |