| atomic clock |
an extremely accurate timekeeping device regulated by the reliably constant frequency at which atoms of certain highly reactive substances absorb or emit electromagnetic radiation. |
| audio frequency |
a frequency in this range. [1/2 definitions] |
| bell-shaped curve |
a graphic representation of a statistically normal frequency distribution, which resembles the outline of a bell; bell curve. |
| booster |
a device for amplifying radio frequency. [1/4 definitions] |
| Brazilian wandering spider |
any of a family of highly venomous, quick-moving, and aggressive spiders native to the rainforests of Brazil, also known as the banana spider for the frequency with which members of this family are found in bunches of bananas. |
| channel |
a broadcasting frequency band. [1/8 definitions] |
| coaxial cable |
a high-frequency electronic transmission cable that has two layers of conductive material, one inside the other and separated by insulation. |
| collocation |
in linguistics, the tendency of certain words to occur together in speech or writing with more frequency than chance would predict, or the particular ways that words tend to combine with each other within a particular language. [1/2 definitions] |
| constantly |
regularly or with very great frequency. [1/3 definitions] |
| continual |
occurring with frequency and regularity. [1/2 definitions] |
| corpus |
a compilation of written or spoken texts in electronic format analyzed as linguistic data in order to learn about word meaning and usage, word frequency, and language patterns. [1/4 definitions] |
| decile |
in statistics, any of the values that divide a frequency distribution into ten groups of equal frequency, or any one of these groups. |
| delta wave |
a low-frequency electric brain wave present during deep sleep in normal adults; delta rhythm. |
| dielectric heating |
the heating of electrically nonconducting materials by exposure to a high-frequency, alternating electromagnetic field, as in the production of plywood. |
| Doppler effect |
the apparent shift in frequency of waves, as of sound or light, if the source and receptor are in motion relative to each other. The frequency appears to become greater if they move closer and become less if they move apart. |
| EHF |
abbreviation of "extremely high frequency." |
| ELF |
abbreviation of "extremely low frequency." |
| El Niņo |
an unusually warm Pacific Ocean current that develops near the International Date Line in the center of the ocean and flows east toward Peru and then south along the coast of South America. El Niņo events, which occur every two to seven years approximately, are associated with various negative impacts including damage to the livelihoods of those dependent on fishing and disturbance to regional and global weather patterns, which in turn can increase the incidence of disease and the frequency of destructive weather events. |
| FM |
a system of varying a radio signal's frequency so as to impose the signal on a carrier wave; frequency modulation. [1/2 definitions] |
| gamma ray |
electromagnetic radiation of high energy and frequency, produced by reactions of radioactive atoms or by high energy electrons interacting with matter. |
| genetic drift |
evolutionary change because of mutations that result from random changes in gene frequency in a small population and that become established in that population. |