As nouns the difference between mold and plasm
is that
mold is a hollow form or matrix for shaping a fluid or plastic substance or
mold can be a natural substance in the form of a woolly or furry growth of tiny fungi that appears when organic material lies for a long time exposed to (usually warm and moist) air or
mold can be loose friable soil, rich in humus and fit for planting while
plasm is a mold or matrix in which anything is cast or formed to a particular shape.
As a verb mold
is to shape in or on a mold or
mold can be to cause to become moldy; to cause mold to grow upon or
mold can be to cover with mold or soil.