at·tach·ment
 /əˈtæʧmənt/  noun  ,  pl   -ments
  1 [  count  ] : an extra part that can be used with a machine to make it do a particular job
   The vacuum cleaner attachments help clean in tight spaces.
   I need a longer attachment for the drill.
  2 : strong feelings of affection or loyalty for someone or something
   [  count  ]
    — usually singular
    the baby's attachment to his mother
    They all have a deep attachment to the old house.
   
   [  noncount  ] People need emotional attachment.
  3 [  count  ] : a document or file that is sent with e-mail
   I'll send the document as an attachment to my next e-mail.
  4 a [  count  ] : a part that is used to connect or attach something
   The attachments that connect the rack to the car are rusted and should be replaced.
  4 b [  noncount  ] : the act of connecting or attaching something
   There are two brackets for attachment of the shelf.
  on attachment
    Brit   : working for a limited time in a particular place
    — usually + to
    She's on attachment to Australia for a month.