Evening star and Vesper

Evening star noun - A planet (usually Venus) seen at sunset in the western sky.

Vesper is a synonym for evening star in planet seen in west at sunset topic. In some cases you can use "Vesper" instead a noun phrase "Evening star".

Vesper noun - A late afternoon or evening worship service.

Evening star is a synonym for vesper. You can use "Evening star" instead a noun "Vesper".