Plausible (adjective)

1. Seemingly reasonable or probable; credible.
2. Able to be thought of as true or possible.

Origin:

From middle french plausible, from latin plausibilis, from plausus ("approved, commended"), from plaudere ("to applau.d")

Examples:

1. The explanation for the delay seemed plausible.
2. The story was plausible but it turned out to be a lie.
3. The defense presented a plausible argument.
4. The theory was plausible but it was later disproved.
5. The excuse was plausible, but the teacher didn't buy it.