U-boat
Nickname given to the General Electric Universal Series diesel-electric locomotives.
Entries starting with U
123 entries.
UART
Acronym of universal asynchronous receiver transmitter.
UBC
nameConstruction
Initialism of Uniform Building Code.
UC
Initialism of ultra capacity.
UCAS
nounRobotics
Initialism of uncrewed combat aerial system, unmanned combat aerial system, uncrewed combat aircraft system, or, unmanned combat aircraft system
UCAV
nounRobotics
Initialism of unmanned/uncrewed combat aerial vehicle.
UDS
nounAutomotive
Initialism of Unified Diagnostic Services.
UE
Initialism of User Equipment (in UMTS).
UFD
Initialism of USB Flash Drive.
UHF
Initialism of Ultra High Frequency.
UHV
Initialism of ultra-high voltage.
ULA
Initialism of United Launch Alliance.
ULCV
nounAutomotive
Initialism of ultralight combat vehicle or ultra-lightweight combat vehicle
ULEZ
Acronym of ultra low emission zone, an area in central London subject to stringent exhaust emission standards for motor vehicles; it was extended in 2023 to include all of Greater London.
ULF
Initialism of Ultra Low Frequency, the band of radio waves between 300 hertz and 3000 hertz.
ULSI
Abbreviation of ultra large scale integration.
ulster
nounManufacturing
A long, loose overcoat made of wool or other rough material, often called a greatcoat, which sometimes features an attached shoulder cape covering the back and sleeves, and which can sometimes be buttoned in front.
ultra high frequency
The frequency area from 300 MHz through 3 GHz, commonly used for TV broadcasting.
ultra large scale integration
An integration type for digital circuits that contain more than one million transistors providing hundreds of thousands of logic gates per chip.
ultra low frequency
Ultra Low Frequency, the band of radio waves between 300 hertz and 3000 hertz.
ultrapotassic
adjectiveMining and extraction
Having a very high potassium content.
ultrasonic bath
A piece of industrial or laboratory equipment that consists of a container, or bath, used for cleaning, mixing, or homogenisation of objects or substances by sending ultrasonic vibrations through the liquid contained in it.
umbilical
A cord connecting an astronaut to a spacecraft, or a craft to ground control prior to launch, etc.
umbilical cord
The line that supplies an astronaut with oxygen and communications when outside a spacecraft.
umbilicus
A tube connecting an astronaut or spacecraft to the mothership, through which supplies and samples can be transferred.
UMTS
Initialism of Universal Mobile Telecommunications System.
unable
Indicating that a requested course of action is not possible to carry out.
unballasted
adjectiveMarine and shipyard
Not loaded or stabilised with ballast.
unbaste
verbManufacturing
To undo the basting of; to remove long or loose stitches from.
unbasted
adjectiveManufacturing
Not basted; not given long loose stitches.
unberth
To remove a spaceship from a dock/berth/mount/mooring with the assistance of a device that moves the spaceship away from its fixed location.
unbuttressed
adjectiveForestry and timber
Not buttressed; having a trunk without a flared base
uncanny valley
nounRobotics
A range of appearances, mannerisms, or behaviors of a humanoid figure that are subtly different from a human and thereby cause feelings of discomfort, such as fear or revulsion.
uncapping
Wax removed from a honeycomb.
unclocked
adjectiveIndustrial electronics
Not measured or regulated by a clock; asynchronous.
under glass
prep phraseAgricultural equipment
In a greenhouse, a cold frame, or a similar structure; said of the propagation and growth of plants.
under square
adjectiveAutomotive
Of internal combustion engine designs, having the bore less than the stroke: that is, having the piston's diameter less than its travel distance.
underactuate
To make less easily actuated or responsive.
underback
nounManufacturing
A vessel that receives the wort as it flows from the mashing tub.
underboard
nounConstruction
A board that lies beneath something.
underburdened
adjectiveMining and extraction
Having too powerful an explosive for the amount of rock broken up, resulting in a risk of igniting dust and gasses.
underbust
nounManufacturing
The circumference of a woman's chest, measured under the breasts.
undercast
An air-passage crossing a road in a mine by means of an airtight box or channel beneath it.
undercloak
nounConstruction
A fixed underlayer of tile or fibre cement on a roof, to support the mortar above.
undercollar
Part of a garment that goes under the collar.
undercutter
A device for cutting into rock walls from below.
underdraught
nounMetallurgy
The situation where part of a formed or cast shape has a reverse taper or inward‑leaning surface that makes it difficult to remove from the die or mold.
underfire
To fire at a low (or excessively low) temperature.
underfired
adjectiveIndustrial ceramics
Fired at a low (or excessively low) temperature.
underfiring
The state of being insufficiently fired or underfired.
underhand
nounManufacturing
The lower of two hands, the hand under the work.
underhole
To cut away or mine out the lower portion of a coal seam or a part of the underlay so as to win or get the overlying coal.
underkill
nounManufacturing
Insufficient disposal because of inadequate inspection criteria.
underlay
A piece of paper pasted under woodcuts, stereotype plates, etc. in a form, to bring them up to the necessary level for printing.
underlayer
A perpendicular shaft sunk to cut the lode at any required depth.
underlooker
A daily inspector of a mine.
underprint
adjectiveIndustrial printing
The addition of colour under black areas to produce a deeper black and prevent oversaturation of the paper.
underride
nounAutomotive
A vehicle accident in which one vehicle partially slides underneath another.
undershift
A misalignment resulting from failure to shift gears far enough.
underslip
An underlying layer of slip.