accepted as normal or usual:
We paid them the standard rate.
standard practice/procedure (=the usual way of doing things)
Searching luggage at airports is now standard practice.
The format is fairly standard.
regular and usual in shape, size, quality etc [≠ non-standard]:
We make shoes in standard and wide sizes.
All these vans are made to a standard design.
a standard book, work etc is read by everyone studying a particular subject
the standard form of a language is the one considered to be correct and is used by most people [≠ non-standard]:
the standard spelling
standard English pronunciation