Hypothesis (noun)

1. A supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.
2. A theoretical idea or explanation.

Origin:

Late 16th century: via latin from greek hupothesis, from hupo "under" + thesis "a proposition".

Examples:

1. The scientist presented his hypothesis about the origin of the universe.
2. The hypothesis was based on the assumption that light travels at a constant speed.
3. The researchers tested their hypothesis by conducting experiments.
4. The hypothesis was proven to be incorrect after further investigation.
5. The hypothesis remains to be one of the most widely accepted theories in physics.