A theory:

Occurs with unvarying uniformity under ideal conditions.

Explains why events occur in nature.

Does not have to have the agreement of the scientific community.

asks a question that needs to be answered.

Is the result of one single well proven and well-accepted hypothesis.

A theory is the result of one single well proven and well-accepted hypothesis.

Explanation:

A theory Is the result of one single well-proven and well accepted - hypothesis.

A theory is a well accepted hypothesis which is also well proved, which tries to explain something based on a known principle.

A theory can have one or more hypotheses that are supported by some repeating testing.

A theory can never be shown as wrong in any context, and if it is wrong, then the theory is widely disproven.

Theories can even derive and evolve, and does not imply the older theories to be wrong, new discovered experiments or idea just get added to the previous theories.