mdf

As a noun replacement is

a person or thing that takes the place of another; a substitute.

As a proper noun kitchen is

.

As a noun hardboard is

a high-density chipboard.

As nouns the difference between ply and mdf

is that ply is a layer of material while MDF is medium density fibreboard.

As a verb ply

is to bend; to fold.

As an initialism idf

is (military|iceland) (iceland defense force).

As nouns the difference between mdf and plyboard

is that mdf is medium density fibreboard while plyboard is a material made from wooden boards glued together.

As a noun fiber

is (countable) a single elongated piece of a given material, roughly round in cross-section, often twisted with other fibers to form thread.