common (shared) / common (widespread) / common (popular) / common (of low class) / communal

(law) common law

(figuratively) common purse, kitty (communal fund)

(education) core curriculum (courses or other components of an educational program which are foundational, prerequisite, or mandatory, as opposed to the elective, secondary, or variable components of a program)

common fig (Ficus carica)

common hippopotamus (Hippopotamus amphibius)

European beaver (Castor fiber)

common beech, European beech (Fagus sylvatica)

European bullhead (Cottus gobio)

common ash, European ash (Fraxinus excelsior)