Common (adjective)

1. Belonging to or shared by two or more people, communities, or other groups.
2. Widespread; occurring frequently.
3. Of low or inferior quality or value.
4. Of or belonging to the people as a whole rather than to any particular individual or class.

Origin:

Late middle english (in the sense "belonging to the community, public"): from old french comun, from latin communis, from com- "together" + unus "one".

Examples:

1. A common language is an important factor in promoting unity.
2. Common sense is the ability to make good judgments.
3. The problem of poverty is a common concern of all nations.
4. The view from the top of the hill is common to both cities.
5. It is common knowledge that exercise is good for health.