What does "stand for" mean?

Represent, symbolize, as in The stars and stripes stands for our country. [Early 1600s]

Advocate, support, uphold, as in The National Writers Union stands for freedom of the press. [c. 1300] Also see stand up for.

Put up with, tolerate. This usage is generally in a negative context, as in Mother will not stand for rude behavior. [Late 1800s] Also see hold still for.

stand for something. Have some value or importance, as in She realized that appearances do stand for something. This usage dates from the mid-1800s but was preceded by stand for nothing, meaning “be worthless,” dating from the late 1300s. Also see stand in for.