What does arsenic mean?
Arsenic is a chemical element with the symbol As and atomic number 33, classified as a metalloid because it shares properties with both metals and non-metals. In its elemental form it appears as a brittle, steel-grey crystalline solid, but it is best known for the extreme toxicity of many of its compounds, particularly arsenic trioxide — historically the substance behind countless cases of deliberate poisoning. Because arsenic compounds are tasteless, colourless when dissolved, and once difficult to detect, they earned a sinister reputation as tools of murderers; only the development of the Marsh test in the nineteenth century made detection reliable. Today arsenic appears more often in environmental and industrial contexts: it contaminates groundwater in parts of South Asia and elsewhere, and it has uses in semiconductors, wood preservatives, and pesticides, though many such uses have been curtailed on health grounds. The word also functions adjectivally, as in 'arsenic compounds', and figuratively evokes treachery and hidden danger.
A chemical element (symbol As, atomic number 33), a brittle grey metalloid whose compounds are highly poisonous.
"Arsenic accumulates in the tissues of fish exposed to contaminated water."
In chemistry contexts, 'arsenic' refers to the element; in everyday usage it often means arsenic trioxide or another poisonous compound.
Arsenic trioxide or a preparation of arsenic compounds, especially regarded as a poison.
"Rat poisons once commonly contained arsenic before safer alternatives were developed."
Relating to or containing arsenic, especially in the +5 oxidation state in chemical nomenclature.
"Arsenic acid is an oxidized form of the element used in some industrial processes."
In strict chemical nomenclature, 'arsenic' as a prefix denotes the higher (+5) oxidation state, contrasted with 'arsenous' for the +3 state; more broadly, 'arsenical' serves as the general adjective.
Rarely used; 'arsenics' occasionally appears to refer to different compounds or preparations of arsenic, but the noun is normally uncountable.
"Early toxicologists catalogued various arsenics used in household preparations."
For centuries arsenic was called 'inheritance powder' — because so many impatient heirs used it to hurry along their fortunes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of arsenic
The word arsenic entered English via Old French and Latin from Greek 'arsenikon', which named the yellow pigment orpiment (arsenic trisulfide). The Greek term may derive from Persian/Aramaic words for gold-yellow, though some scholars connected it to the Greek 'arsen' meaning male. It was adopted into medieval Latin alchemy and reached English in the Middle Ages as a name for the mineral and later the element itself. Related English forms include arsenate, arsenious, and arsenical.
Related word forms
How arsenic is actually used
As an adjective, 'arsenic' describes things containing or relating to arsenic (e.g. 'arsenic compounds'). The element itself occurs in both metallic and non-metallic forms; its toxicity comes chiefly from its compounds rather than the pure element. The word carries strong connotations of poison and murder mystery plots.
Easily confused with arsenic
An arsenal is a collection of weapons or military equipment, whereas arsenic is the poisonous chemical element.