The most common and most likely answer to this crossword clue is the 6 letter word CUSTOM
I've seen this crossword clue in The Times
C
U
S
T
O
M
More clues leading to the result CUSTOM
- Copper with most unusual habit.
- Copper’s cat’s habitual practice
- Trade convention
- Curse abrupt chap’s way of behaving
- Copper with most unusual habit
- Copper checks over practice
- Confined in nick, sons honour tradition
- Copper starts to suspect traffic officer’s methadone habit
- Trade in copper — order placed by good man
- Copper most unpredictable, one’s regularly observed
Buddy explains!

The straight part
We know that "habit" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case habit = custom.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CUSTOM mean?
CUSTOM noun- Frequent repetition of the same behavior; way of behavior common to many; ordinary manner; habitual practice; method of doing, living or behaving.
- Traditional beliefs or rituals
- Habitual buying of goods; practice of frequenting, as a shop, factory, etc., for making purchases or giving orders; business support.
- Long-established practice, considered as unwritten law, and resting for authority on long consent; usage. See Usage, and Prescription.
- Familiar acquaintance; familiarity.
- Toll, tax, or tribute.
- To make familiar; to accustom.
- To supply with customers.
- To pay the customs of.
- To have a custom.
- Created under particular specifications, specially to fit one's needs: specialized, unique, custom-made
- Own, personal, not standard or premade
- Accustomed; usual