Definitions of defect:

• noun:   a failing or deficiency

  Example: "That interpretation is an unfortunate defect of our lack of information"

• noun:   an imperfection in a bodily system

  Example: "Visual defects"

• noun:   an imperfection in a device or machine

  Example: "If there are any defects you should send it back to the manufacturer"

• noun:   a mark or flaw that spoils the appearance of something (especially on a person's body)
• verb:   desert (a cause, a country or an army), often in order to join the opposing cause, country, or army