A "strawman argument" or simply a "strawman" is a flimsy argument which
is created only to be "knocked down".

The term is sometimes used to refer to simplified arguments which are
then demolished to understand exactly where they fall apart. What is
learned in the process may then be applied to a related, more
sophisticated argument, either to show how it may be similarly
demolished or to illustrate its relative strength.

More frequently the term comes up in relation to phony, easily
countered arguments which are attributed in debate to an opponent and
then demolished -- thereby "proving" that the opponent's claims are
empty.

Example: Creationists disprove evolution by attributing the claim to it
that monkeys will sometimes give birth to human babies, which is false,
and therefore evolution is false. Since nothing claimed by most
evolutionists implies such a thing, this is a counter-argument to a
strawman.