Comment: Then you don't know how to

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Then you don't know how to

Then you don't know how to read a definition.

Words can have different independent meanings.
Yes a civilian is defined as

ci·vil·ian (s-vlyn)
n.
1. A person following the pursuits of civil life, especially one who is not an active member of the military, the police, or a belligerent group.
2. A person who does not belong to a particular group or engage in a particular activity.
3. A specialist in Roman or civil law.

This doesn't mean all civilians are presumed to be experts in Roman or civil law.

It means a civilian is presumed to be in one or more of the three subsets.