What is the meaning of the word "true"?

Definitions:

accurately placed or thrown adjective
- My aim was true.
as acknowledged adverb
- True, you are the smartest in our class.
conforming to definitive criteria adjective
- the horseshoe crab is not a true crab
devoted (sometimes fanatically) to a cause or concept or truth adjective
- true believers bonded together against all who disagreed with them
expressing or given to expressing the truth adjective
- a true statement
make level, square, balanced, or concentric verb
- true up the cylinder of an engine