| 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] |
| fret2 |
an interlaced, angular design used as decoration, esp. as cut out of wood with a fret saw; fretwork. [3 definitions] |
| fret3 |
one of the ridges set across the fingerboard of a stringed instrument, such as a guitar or lute, that is played by hand. [2 definitions] |
| fretful |
inclined to worry anxiously, or to be irritable. |
| fret saw |
a fine-toothed saw with a narrow blade set in a U-shaped frame, used to cut ornamental patterns in wood and other materials. |
| fretwork |
ornamental openwork composed of interlacing bars in a repeated, geometric pattern. |
| Freudian |
of or relating to Freud or to his psychoanalytic theories or practices. [2 definitions] |
| Freudian slip |
a mistake in speech that is thought to reveal unconscious motives, wishes, or the like. |
| FRG |
abbreviation of "Federal Republic of Germany," from 1949 to 1990, a central European country, formerly also known as West Germany, located between France and East Germany, now part of reunited Germany. |
| Fri. |
abbreviation of "Friday," the sixth day of the week, occurring between Thursday and Saturday. |
| friable |
easy to crumble, break, or reduce to powder; crumbly, as certain rocks. |
| friar |
a member of a male Roman Catholic religious order, esp. the Franciscan and Dominican mendicant orders; monk. |
| friar's lantern |
an elusive light that hovers over marshes at night; ignis fatuus. |
| friary |
a monastery or brotherhood of friars. |
| fricandeau |
a veal loin that has been larded and braised or roasted. |
| fricassee |
lightly browned poultry or meat that is stewed and served in gravy. [2 definitions] |
| fricative |
in phonetics, pronounced with a rush of air through a narrow slit or passage formed within the mouth. [2 definitions] |
| friction |
the rubbing of surfaces against each other. [3 definitions] |