Standard has 15 different meanings across 3 categories:
a basis for comparison; a reference point against which other things can be evaluated
"the schools comply with federal standards"
"they set the measure for all subsequent work"
a board measure = 1980 board feet
"The lumberyard manager told us that their entire shipment of oak beams totals exactly one standard, which equals 1,980 board feet."
the value behind the money in a monetary system
"The bank was forced to issue new currency after hyperinflation destroyed the standard of the old bills."
an upright pole or beam (especially one used as a support)
"distance was marked by standards every mile"
"lamps supported on standards provided illumination"
A principle or example or measure used for comparison.
"The company's new pricing model was rejected because it failed to align with industry standards for fair competition."
A level of quality or attainment.
"The university admitted that their teaching standards had slipped significantly in recent years."
In plain English: A standard is an accepted level of quality that something should reach.
"The hotel room had two beds that were slightly above standard size."
Usage: Use this noun to refer to an accepted model against which other things are measured, such as industry standards or safety standards. It often describes a specific benchmark rather than the general concept of conformity found in its adjective form.
conforming to or constituting a standard of measurement or value; or of the usual or regularized or accepted kind
"windows of standard width"
"standard sizes"
"the standard fixtures"
"standard brands"
"standard operating procedure"
established or well-known or widely recognized as a model of authority or excellence
"a standard reference work"
"the classical argument between free trade and protectionism"
Falling within an accepted range of size, amount, power, quality, etc.
"The restaurant's portion sizes are standard for a chain, so everyone left feeling just as full regardless of their table order."
In plain English: Something that is standard follows the usual rules or expectations for how things should be done.
"The apartment has standard white kitchen cabinets and a basic bathroom."
An expression of agreement
"He nodded and gave a standard when I asked if we could leave early."
The word standard comes from the Frankish phrase standahard, which literally meant "stand firm." It entered English via Old French as a term for a battle flag or gathering place.