indolence
Habitual laziness and avoiding work or effort on purpose.
Indolence is habitual laziness or a settled unwillingness to work or exert yourself. An indolent person consistently avoids effort, not because they're tired from hard work, but because they've developed a pattern of doing as little as possible.
This goes beyond normal tiredness or taking a well-earned rest. After running a marathon, you're exhausted and need recovery. That's not indolence. But if you regularly skip your responsibilities, let others do your share of group projects, or always find excuses to avoid helping with chores, that's indolence creeping in.
The word carries a tone of disapproval because indolence wastes potential. An indolent student might be perfectly capable of learning but consistently avoids homework and studying. An indolent teammate might have the skills to contribute but regularly finds ways to slack off while others carry the load.
The opposite of indolence is diligence: steady, earnest effort over time. While everyone feels lazy occasionally, indolence describes someone who has made avoiding work their default approach to life. It's a habit that, once formed, can be surprisingly hard to break.