a large commercial ship (especially one that carries passengers on a regular schedule)
observation tower
Noun
a structure commanding a wide view of its surroundings
observatory
Noun
a structure commanding a wide view of its surroundings
observatory
Noun
a building designed and equipped to observe astronomical phenomena
ostensorium
Noun
(Roman Catholic Church) a vessel (usually of gold or silver) in which the consecrated Host is exposed for adoration
off-roader
Noun
a bicycle with a sturdy frame and fat tires
ordnance store
Noun
military supplies
orphans' asylum
Noun
a public institution for the care of orphans
orphenadrine
Noun
a skeletal muscle relaxant (trade name Norflex) used to treat severe muscle strain and Parkinsonism
omnirange
Noun
a navigational system consisting of a network of radio beacons that provide aircraft with information about exact position and bearing
oboe
Noun
a slender double-reed instrument
omnidirectional range
Noun
a navigational system consisting of a network of radio beacons that provide aircraft with information about exact position and bearing
orphrey
Noun
a richly embroidered edging on an ecclesiastical vestment
oboe da caccia
Noun
an alto oboe
omnidirectional radio range
Noun
a navigational system consisting of a network of radio beacons that provide aircraft with information about exact position and bearing
orrery
Noun
planetarium consisting of an apparatus that illustrates the relative positions and motions of bodies in the solar system by rotation and revolution of balls moved by wheelwork
oboe d'amore
Noun
an oboe pitched a minor third lower than the ordinary oboe
one-spot
Noun
a domino or die whose upward face shows one pip
orthicon
Noun
a now obsolete picture pickup tube in a television camera
observation dome
Noun
lookout consisting of a dome-shaped observatory
one-way street
Noun
a street on which vehicular traffic is allowed to move in only one direction
one-way street
Noun
unilateral interaction
onion dome
Noun
a dome that is shaped like a bulb
orthochromatic film
Noun
a photographic film sensitive to green and blue and violet light
obstacle
Noun
an obstruction that stands in the way and must be removed, surmounted or circumvented
obstacle
Noun
something immaterial that stands in the way and must be circumvented or surmounted
op art
Noun
a style of abstractionism popular in the 1960s
orthopter
Noun
heavier-than-air craft that is propelled by the flapping of wings
obstructor
Noun
any structure that makes progress difficult
obstructor
Noun
someone who systematically obstructs some action that others want to take
open-air market
Noun
a public marketplace where food and merchandise is sold
ornithopter
Noun
heavier-than-air craft that is propelled by the flapping of wings
open-air marketplace
Noun
a public marketplace where food and merchandise is sold
orthoscope
Noun
an ophthalmoscope with a layer of water to neutralize the refraction of the cornea
obstructer
Noun
any structure that makes progress difficult
obstructer
Noun
someone who systematically obstructs some action that others want to take
oscillator
Noun
generator that produces sonic oscillations or alternating current
open circuit
Noun
an incomplete electrical circuit in which no current flows
oscillogram
Noun
the recording produced by an oscillograph
obturator
Noun
a prosthesis used to close an opening (as to close an opening of the hard palate in cases of cleft palate)
open-end wrench
Noun
a wrench having parallel jaws at fixed separation (often on both ends of the handle)
oscillograph
Noun
a device for making a record of the wave forms of fluctuating voltages or currents
obverse
Noun
the side of a coin or medal bearing the principal stamp or design
obverse
Noun
the more conspicuous of two alternatives or cases or sides
oscilloscope
Noun
electronic equipment that provides visual images of varying electrical quantities
opener
Noun
a hand tool used for opening sealed containers (bottles or cans)