A colloid in which bubbles of gas are suspended in a solid or liquid.
Foam Inhibitor
An additive which causes foam to dissipate more rapidly.
Focal Chord
A chord of a conic that passes through a focus.
Focal Length
The distance from a mirror or the centre of a lens to its focal point.
Focal Plane
A surface upon which the image of all points in the field of view of an optical instrument is created.
Focal Point
The location at which a mirror or a lens focuses rays parallel to the optic axis or from which such rays appear to diverge.
Focal Radius
A line segment from the focus of an ellipse to a point on the perimeter of the ellipse.
Point at which converging rays meet and at which a clearly defined image can be obtained.
Focusing Anode
An electrode of a CRT that is used to focus the electrons into a tight beam.
A young animal growing inside it′s mother, a foetus will have the same overall shape and parts of it′s parents.
Folded Dipole
An ordinary half-wave antenna that has one or more additional conductors connected across the ends parallel to each other.
Food Additive
A substance that is added to foods to improve colour or to make it last longer.
Food Chain
A list of organisms showing how each depends on another for food.
Food Grade Lubricants
Lubricants acceptable for use in meat, poultry and other food processing equipment, applications and plants.
Food Web
A diagram showing how organisms depend on lots of other living things for food.
Fools Gold
Name given to Iron II Sulphide due to its colour and texture.
One foot was defined as one third of the Imperial Standard yard.
Foot Brake
Vehicle brake applied with the foot.
Foot Candle
A measure of light intensity on a surface being illuminated.
Foot of Altitude
The intersection of an altitude of a triangle with the base to which it is drawn.
Foot of Line
The point of intersection of a line with a line or plane.
Foot Pound
Imperial unit of mechanical energy.
Foot Poundal
Unit of work, equal to the work done by a force of one poundal acting through a distance of one foot.
Foot Switch
A foot operated switch.
The stones at the base of a bridge structure that take the loads onto the foundations.
The widened base of a foundation that spreads a load from the building across a broader area of soil.
The area occupied by a device or machine.
For Next Loop
A programming language statement which allows code to be repeatedly executed.
Forbes, Prof George
Invented carbon brush used in electric motors and designed the electrification system for London Underground.
A force is that which when acting on a body that is free to move accelerates the motion of the body.
Force Feed Lubrication
A system of lubrication in which the lubricant is supplied to the bearing surface under pressure.
Force Fit
A fitting which one part is forced of pressed into another to form a single unit.
Force Window
A special windowing function for minimizing noise in impact testing.
Forced Heat Convection
If the flow of gas away from a hot object starts by itself it is called natural convection. However, if the gas is forced past the object it is called forced convection.
Forced Response Analysis
Mathematically calculating the system response to an arbitrary forcing function using modal analysis data as the system model.
Forced Vibration
The oscillation of a system under the action of a forcing function.
Forcing Frequency
In sinusoidal vibration testing or resonance searching, the frequency at which a shaker vibrates.
Lies between low and high tide marks.
The blacksmith′s workshop. Also meaning to forge a workpiece.
Forge Welding
A group of welding processes in which fusion is produced by heating in a forge or furnace and applying pressure or blows.
Mechanical forming of a metal or alloy by heating and hammering.
The relative ease with which a metal can be shaped through plastic deformation.


Used widely by industry to manufacture building materials and numerous household products. It is also a by-product of the incomplete combustion of carbo containing materials.

Formation Reaction
A reaction that forms one mole of a compound from its elements in their most stable forms.
Formed Cutters
Milling cutters which will produce shaped surfaces with a single cut.
Formic Acid
Another name for Methanoic Acid.
Formic Anammonide
Alternative name for Hydrogen Cyanide.
Alternative name for Hydrogen Cyanide.
A concise statement expressing the symbolic relationship between two or more quantities.
Formula Unit
One formula weight of a compound.
Formula Weight
The formula weight is the sum of the atomic weights of the atoms in an empirical formula.
Formyl Trichloride
Alternative name for Chloroform.
Formylic Acid
Another name for Methanoic Acid.
Forrester, Jay W
Pioneer in early digital computer development and invented random-access, coincident-current magnetic storage, which became the standard memory device for digital computers.
Forstner Bit
These have a centre spur and circular rims with cutting teeth that cut clean flat bottomed holes.
From Formula Translation this is a computer programming language that is best known amongst scientists and engineers. Within the engineering community it is being replaced by packages such as Matlab.
Forward Bias
The bias applied between the base and emitter of a transistor to coincide with the P and N zone polarities.
Forward Resistance
The smaller resistance value observed when you are checking the resistance of a semiconductor.
Fossil Carbon Dioxide Emissions
Emissions of carbon dioxide resulting from the combustion of fuels from fossil carbon deposits such as oil, natural gas, and coal.
Fossil Fuel
A fuel such as coal, oil or natural gas that was formed through the decomposition of ancient plant and animal life.
Fossil Fuel Emissions
Emissions of greenhouse gases resulting from the combustion of fuels from fossil carbon deposits.
Foster Seeley Discriminator
A circuit that uses a double-tuned RF transformer to convert frequency variations in the received FM signal to amplitude variations.
Foucault Currents
Also known as Eddy Currents.
The portion of a building that has the sole purpose of transmitting structural loads from the building into the earth.
Foundation Ring
The base of the firebox, where the inner and outer shells are joined.
Foundation Stiffness
A term used to refer to the stiffness of a machine support or the region of contact between a structure and its surroundings.
Four Colour Theorem
It is desired to colour a political map on a plane so that countries sharing a common boundary are coloured differently.
Four Element Array
An antenna array with three parasitic elements and one driven element.
Four High Mill
Common rolling mill for reducing the thickness of aluminum sheet consisting of two large diameter work rolls which are supported by even larger back-up rolls.
Four Wheel Drive
All four wheels are driven by the engine.
Four Wheel Steering
A mechanism that allows the rear wheels to steer along with the front wheels.
Fourier Analysis
A mathematical analysis of waves, discovered by the French mathematician Fourier (1768-1830).
Fourier, Baron Jean Baptiste Joseph
French mathematician and physicist who formulated a method for analyzing periodic functions and studied the conduction of heat.
Fourier Series
Decomposes periodic functions or periodic signals into the sum of a set of simple oscillating functions.
Fourier Transform
The mathematically rigorous operation which transforms from the time domain to the frequency domain and vice versa.
Fourier′s Law
Empirical relationship between the conduction rate in a material and the temperature gradient in the direction of energy flow.
Four-Stroke Engine
An engine operating on a cycle which is completed in four strokes, or two revolutions of the crankshaft.
Fourth State of Matter
Plasma are sometimes referred to as the fourth state of matter.
The central portion of the retina where visual acuity, or the ability to distinguish small objects and details, is greatest. Only about half a millimetre in diameter, the fovea is the retina′s "rod-free zone" and is densely packed with cones.