Slippery (adjective)

1. Having a smooth, slimy, or oily surface that does not provide good traction or grip.
2. Not easily grasped or held securely, especially because of being constantly changing.
3. Not easy to understand or explain, especially because of being vague or ambiguous.

Origin:

From middle english slipir, from old english slepig, meaning "sliding, slippery.".

Examples:

1. The surface of the wet rocks was slippery and the hiker had to be careful.
2. The stock market was very slippery and it was hard to make accurate predictions.
3. The politician's slippery answer avoided the question completely.
4. The skater was warned about the slippery ice on the rink.
5. The fish was slippery and difficult to handle when it was caught.