Is it grammatically and lexically correct to call a person with a particular habit "a habit holder" or "a habit carrier" for short?
Wow, its actually hard to come up with something to describe a person with "any" habit.
I don't know what you are trying to convey by 'habit' here. A habit of smoking, taking drugs, etc? A habit of interrupting others while they are speaking?
Well, you can give these a try:
- addict (might be a bit extreme but may work for a habit of smoking, doing drugs, watching stuff, etc)
- fanatic (according to Collins: If you say that someone is a fanatic, you mean that they are very enthusiastic about a particular activity, sport, or way of life.)
devotee (google: a person who is very interested in and enthusiastic about someone or something.)
enthusiast (google: a person who is highly interested in a particular activity or subject)
proclivity (google: a tendency to choose or do something regularly; an inclination or predisposition toward a particular thing.)
inveterate (google: having a particular habit, activity, or interest that is long-established and unlikely to change. "he was an inveterate gambler")
congenital (google: (of a person) having a particular trait from birth or by firmly established habit. "a congenital liar")