What is the meaning of the word "habit"?

Definitions:

A behavioral pattern that is learned through repetition and is often almost involuntary. NOUN
- I always buy the same brand of toothpaste out of habit.
A settled or regular tendency or practice especially one that is hard to give up. NOUN
- We stayed together out of habit.
An automatic reaction to a specific situation. NOUN
- Birds have the habit of migrating to warmer regions during the winter months.
An established custom NOUN
- it was their habit to dine at 7 every evening
Refers to clothing of a distinctive style or for a particular occasion. NOUN
- Before visiting the ranch, I bought a new habit riding habit.
- The habit of the monk was adorned with intricate embroidery.