What is the meaning of the word "kink"?

Definitions:

A flaw or obstacle in a plan, operation, etc. NOUN
- We encountered a few kinks in the software development process that needed to be ironed out before the launch.
A quirk of character or behavior. VERB
- His kink for organizing everything into lists made him an excellent planner, though sometimes a bit predictable.
A sharp twist or curve in something that is otherwise straight. NOUN
- The garden hose stopped working because there was a kink in it that blocked the water flow.
A stiffness in the neck, back, etc. NOUN
- After a long day at the computer, she had a kink in her neck that made it painful to turn her head.
Can refer to a twist or wrinkle in fabric that affects its appearance or usability. NOUN
- The silk dress had a kink that couldn't be smoothed out, even with ironing.
Describe a twist in a plot or character's development that adds complexity or intrigue. NOUN
- The story took a kink towards the end, revealing the protagonist's true motives and surprising the readers.
Something that is wrong. NOUN
- Pete still needs to iron out a few kinks in his game.