stan·dard 
(stăndərd)
(stăndərd)adj.
1. Serving as or conforming to an established or accepted measurement or value: a standard unit of volume.
2. Widely recognized or employed as a model of authority or excellence: a standard reference work.
3. Acceptable but of less than top quality: a standard grade of beef.
4. Normal, familiar, or usual: the standard excuse.
5. Commonly used or supplied: standard car equipment.
6. Linguistics Conforming to models or norms of usage admired by educated speakers and writers: standard pronunciation.
n.
1.
a. An acknowledged measure of comparison for quantitative or qualitative value; a criterion. See Synonyms at ideal.
b. An object that under specified conditions defines, represents, or records the magnitude of a unit.
2.
a. The commodity or commodities used to back a monetary system.
b. The set proportion by weight of gold or silver to alloy metal prescribed for use in coinage.
3.
a. A degree or level of requirement, excellence, or attainment: Their quality of work exceeds the standards set for the field.
b. Something, such as a practice or a product, that is widely recognized or employed, especially because of its excellence.
c. A set of specifications that are adopted within an industry to allow compatibility between products.
d. A requirement of moral conduct: the standards of polite society.
4. A flag, banner, or ensign, especially:
a. The ensign of a chief of state, nation, or city.
b. A long, tapering flag bearing heraldic devices distinctive of a person or corporation.
c. An emblem or flag of an army, raised on a pole to indicate the rallying point in battle.
d. The colors of a mounted or motorized military unit.
5. Chiefly British A grade level in elementary schools.
6. A pedestal, stand, or base.
7. The large upper petal of the flower of a pea or related plant. Also called banner, vexillum.
8. One of the narrow upright petals of an iris.
9. A shrub or small tree that through grafting or training has a single stem of limited height with a crown of leaves and flowers at its apex.
10. Music A composition that is continually used in repertoires: a pianist who knew dozens of Broadway standards.
[Middle English, flag, banner, standard measure (perhaps from the use of flags as points of reference in battle) , from Old French estandard, flag marking a rallying place, from Frankish *standhard, probably originally meaning standing firmly, steadfast : *standan, to stand; see stā- in the Appendix of Indo-European roots + *hard, firm, hard; see kar- in the Appendix of Indo-European roots.]
standard·ly adv.