1. an acquired behavior pattern regularly followed until it has become almost involuntary:

The habit of looking both ways before crossing the street.

2. an established custom;

“It was their habit to dine at 7 every evening”

The garb of a particular rank, profession, religious order, etc.:

a monk’s or nun’s habit.

The attire worn by a rider of a saddle horse.

It was a habit they went to see parents every Sunday.

2. A pattern of behavior acquired through frequent repetition

She had the habit of always tapping her fingers.

3. A distinctive attire.

Many nuns don’t wear a habit.

4. Substance abuse.

His smoking habit will kill him.