astray
Off the right path or plan, or doing wrong.
To go astray means to wander off the right path or to get lost, either literally or figuratively. When hikers go astray on a trail, they've veered off course and might not know where they are. When a letter goes astray in the mail, it gets sent to the wrong address.
The word often describes losing your way morally or getting pulled into bad decisions. A student might be led astray by friends who encourage skipping class. When someone goes astray, they've drifted from what they know is right or from their original plan.
You'll often see the phrase lead astray, which means to guide someone in the wrong direction, either accidentally or on purpose. A misleading map might lead travelers astray. Bad advice could lead someone astray in their studies.
The word carries a sense that something has gone wrong. A project goes astray when it gets off track from its goals. Plans go astray when unexpected problems arise. The good news is that going astray usually isn't permanent: hikers can find their way back to the trail, and people can correct their course once they realize they've wandered off.