Evergreen oak and Oak tree

Evergreen oak noun - Evergreen oak of southern Europe having leaves somewhat resembling those of holly; yields a hard wood.

Oak tree and evergreen oak are semantically related. In some cases you can use "Oak tree" instead a noun phrase "Evergreen oak".

Oak tree noun - A deciduous tree of the genus Quercus; has acorns and lobed leaves.

Evergreen oak and oak tree are semantically related. Sometimes you can replace phrase "Evergreen oak" with "Oak tree", this phrases are similar.