This idiom or expression means:

The whole thing.
All of something.

Also:
The whole enchilada.
The whole nine yards.

Q. What do you want me to get you?
A. Everything. A burger, a large drink, and some fries. The whole nine yards.

This idiom or expression means:

Completely.
The whole thing.

When someone says “We bought it hook, line, and sinker,” they mean something like “We believed the whole (false) story.”

This expression is used with verbs like buy, accept, fall for, etc., and has to do with being deceived.