1.
An ~ person or place is not looked after or defended, and so they may be harmed or attacked.
What better target than an ~ girl, going along that river walkway in the dark...
The landing beaches would be ~.
ADJ: ADJ n, v-link ADJ, ADJ after v
2.
If something is ~, it is not covered or treated with anything, and so it may easily be damaged.
Exposure of ~ skin to the sun carries the risk of developing skin cancer...
This leaves fertile soil ~ and prone to erosion.
ADJ: ADJ n, v-link ADJ, ADJ after v
3.
If two people have ~ sex, they do not use a condom when they have sex.
ADJ: ADJ n