habit

(noun) an established custom. Synonyms: wont. Examples: "It was their habit to dine at 7 every evening."

(noun) (psychology) an automatic pattern of behavior in reaction to a specific situation; may be inherited or acquired through frequent repetition. Synonyms: use. Examples: "Owls have nocturnal habits." "She had a habit twirling the ends of her hair." "Long use had hardened him to it."

(noun) a distinctive attire worn by a member of a religious order.

(noun) the general form or mode of growth (especially of a plant or crystal). Examples: "A shrub of spreading habit."

(noun) attire that is typically worn by a horseback rider (especially a woman's attire). Synonyms: riding habit.

(noun) excessive use of drugs. Synonyms: substance abuse, drug abuse.

(verb) put a habit on.