damage to the retina resulting from exposure of the eye to the sun without adequate protection
presbyopia
Noun
a reduced ability to focus on near objects caused by loss of elasticity of the crystalline lens after age 45
polyvalence
Noun
(toxicology) the state of being capable of counteracting more than one toxin or antigen or kind of microorganism
polyvalence
Noun
(chemistry) the state of having a valence greater than two
polyvalency
Noun
(toxicology) the state of being capable of counteracting more than one toxin or antigen or kind of microorganism
polyvalency
Noun
(chemistry) the state of having a valence greater than two
physical fitness
Noun
good physical condition
paracentral scotoma
Noun
a scotoma that is adjacent to the fixation point
polyploidy
Noun
the condition of being polyploid
paralysis
Noun
loss of the ability to move a body part
paresis
Noun
a slight or partial paralysis
paraparesis
Noun
a slight paralysis or weakness of both legs
polyphosphoric acid
Noun
a series of oxyacids of phosphorus
polymethyl methacrylate
Noun
a transparent plastic used as a substitute for glass
pyrogallol
Noun
a toxic white lustrous crystalline phenol used to treat certain skin diseases and as a photographic developer
pyrogallic acid
Noun
a toxic white lustrous crystalline phenol used to treat certain skin diseases and as a photographic developer
Perspex
Noun
a transparent thermoplastic acrylic resin
pyrophosphoric acid
Noun
a solid acid formed by reactions of orthophosphoric acid
pyrophosphate
Noun
a salt or ester of pyrophosphoric acid
plexiglass
Noun
a light transparent weather resistant thermoplastic
polyethylene
Noun
a lightweight thermoplastic
polythene
Noun
a lightweight thermoplastic
polyvinyl acetate
Noun
a vinyl polymer used especially in paints or adhesives
polyvinyl chloride
Noun
a polymer of vinyl chloride used instead of rubber in electric cables
phenylethylene
Noun
a colorless oily liquid
polystyrene
Noun
a polymer of styrene
polytetrafluoroethylene
Noun
a material used to coat cooking utensils and in industrial applications where sticking is to be avoided
polyelectrolyte
Noun
an electrolyte of high molecular weight
propanone
Noun
the simplest ketone
prussic acid
Noun
a solution of hydrogen cyanide in water
pina cloth
Noun
a fine cloth made from pineapple fibers
phosphorous acid
Noun
a clear or yellow monobasic acid (H3PO2)
plasticizer
Noun
a substance added to plastics or other materials to make them more pliable
plasticiser
Noun
a substance added to plastics or other materials to make them more pliable
protactinium
Noun
a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
protoactinium
Noun
a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
potassium alum
Noun
a white crystalline double sulfate of aluminum: the potassium double sulfate of aluminum
potash alum
Noun
a white crystalline double sulfate of aluminum: the potassium double sulfate of aluminum
pure gold
Noun
100 per cent gold
palladium
Noun
a silver-white metallic element of the platinum group that resembles platinum
phosphor
Noun
a synthetic substance that is fluorescent or phosphorescent
phosphorus
Noun
a multivalent nonmetallic element of the nitrogen family that occurs commonly in inorganic phosphate rocks and as organic phosphates in all living cells
platinum
Noun
a heavy precious metallic element
plutonium
Noun
a solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons
plutonium 239
Noun
a highly fissionable isotope of plutonium that is used in atomic weapons and as a reactor fuel
polonium
Noun
a radioactive metallic element that is similar to tellurium and bismuth
potassium
Noun
a light soft silver-white metallic element of the alkali metal group
praseodymium
Noun
a soft yellowish-white trivalent metallic element of the rare earth group
promethium
Noun
a soft silvery metallic element of the rare earth group having no stable isotope