da dictionary.com:

shit (sht) Vulgar Slang
v. shit, also shat (sht) shit·ting, shits
v. intr.
To defecate.

v. tr.
To defecate in.

To tease or try to deceive.


n.
Excrement.

The act or an instance of defecating.

shits Diarrhea. Used with the.

Something considered disgusting, of poor quality, foolish, or otherwise totally unacceptable.

A mean or contemptible person.

A narcotic or intoxicant, such as marijuana or heroin.

Things; items.

Foolish, deceiftul, or boastful language.

Insolent talk or behavior.

Trouble or difficulty.

A small or worthless amount: He doesn't know shit.

interj.
Used to express surprise, anger, or extreme displeasure.

Phrasal Verb:
shit on
To treat with malice or extreme disrespect.

Idioms:
get (one's) shit together
To get organized; put one's affairs or possessions in order.
give a shit
To care the least bit.
no shit
Used to express disbelief.

Used to express contemptuous acknowledgment of the obvious.

shit bricks/a brick
To become extremely worried or frightened.
up shit creek (without a paddle)
In dire circumstances with no hope of help.
when the shit hits the fan
When the situation goes awry; when trouble starts.