deficiency
lack of an adequate quantity or number
failing
failure to reach a minimum required performance
loss
the act of losing someone or something
want
the state of needing something that is absent or unavailable
lack
the state of needing something that is absent or unavailable
imperfection
the state or an instance of being imperfect
blemish
a mark or flaw that spoils the appearance of something (especially on a person's body)