What is displace?

Not in general, please be more specific about reaction or circumstances.

in what? without knowing in what system the zinc is replacing iron, the answer cannot be fully given. Only a generalization of Zn and Fe both being in a +2 oxidation state would allow one to replace...

i displace my pencil . meaning that i lost my pencil Water was displaced when I put my hand in the jar.

Foreign outsourcing displaces US engineers.

Yes.