what does THC stand for?

[biohaze420]

Takin Hits Constantly

 

[whatthehellp7]

Transcending human cynic

 

[FreakNature]

trippy hedonistic contraband

 

[J842P]

Isn't delta-9 only one of the canniboniods in THC?

No, THC is usually just a shortened version of delta-9 THC, which is one of the cannabinoids found in the cannabis plant (for example, CBN or cannabinol, is another cannabinoid).
Here's a list of the ones found naturally in the cannabis plant.
Cannabinoids - Wikipedia, the free encyclopedia

 

[Smokin Moose]

And don't forget the poor cousin, Delta 8 THC.