The most common and most likely answer to this crossword clue is the 9 letter word SEDENTARY
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More clues leading to the result SEDENTARY
- Prepared with a line about study describing many office jobs?
- A little light covering garden may in the end become inactive
- Any rested drunk could be this
- Tender, say — moving or not!
- Sun keeping garden dry, ultimately doing little
- Inactive seaman giving garden priority in outskirts of Surrey
- Celebrity going round garden, ending in rockery, sitting down
- One’s ‘not standing’ for this!
- Still in garden in sun before day’s end
- Often sitting in garden in street over a railway
Buddy explains!

The straight part
We know that "lifestyle that might make one unfit" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lifestyle that might make one unfit = sedentary.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 SEDENTARY mean?
SEDENTARY noun- A sedentary person
- Not moving; relatively still; staying in the vicinity.
- (of a human population) Living in a fixed geographical location; the opposite of nomadic.
- (of a job, lifestyle, etc.) Not moving much; sitting around.
- Inactive; motionless; sluggish; tranquil
- Caused by long sitting.