1 accepted as normal or usual :
We paid them the standard rate.
The format is fairly standard.
We paid them the standard rate. standard practice/procedure (=the usual way of doing things)
Searching luggage at airports is now standard practice.
Searching luggage at airports is now standard practice.
The format is fairly standard.2 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.
We make shoes in standard and wide sizes.
All these vans are made to a standard design.3SE a standard book, work etc is read by everyone studying a particular subject
4SL 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
the standard spelling
standard English pronunciation