eclipse
It is called a metaphor.
a buthole
It is called "joining" or "combining" two things together.
perhaps an allegory, or a parable
something is a thing that is some. or one thing that is not everything else.
Such a relationship is parasitic, the one stealing the nutrients is called a parasite, the one being stolen from is called the host.
Could be a hypocrite , refers to people who are considered to be insincere
Something that covers over something else, such as--> When I went to bed, I was envelloped by my blankets.
satellite
Many words come to mind, depending on the situation. Reminiscent. Familiar. Deja vu.
the thing that you do that makes something else do something
It became Congo. The Zaire river is the Congo river. It is the same thing, it is now just called something else.