Define "dielectric" and list the dielectric constant values for vacuum and water

The term dielectric makes reference to materials that are insulators (the charges in the material does not flow freely and for this reason an insulator material cannot conduce electricity). BUT if we applied this material in an electric field they can be polarized.

Dielectric Constant: It is also defined as a relative permittivity and it is the amount of charge required to produce one unit of electric flux( electric field in a surface)  in a given medium.

it is typically denoted as Epsilon (ε)

and its formula is: ε = ε(ω) /ε(0)

where:

ε(ω) = the frequency-dependent permittivity of the material

ε(0) = the dielectric constant value in vacuum

Dielectric Constant values: