1.
If something is ~, nobody is protecting it or looking after it.
I should not leave my briefcase and camera bag ~.
= unattended
ADJ: ADJ after v, v-link ADJ, ADJ n
2.
If you do or say something in an ~ moment, you do or say it carelessly and without thinking, especially when it is something that you did not want anyone to see or know.
The photographers managed to capture Jane in an ~ moment...
ADJ: usu ADJ n