Definition of “attachment” - Learner’s Dictionary

attachment

noun uk us /əˈtætʃmənt/
FEELING [ C, U ]

a feeling of love or strong connection to someone or something:

I wasn't aware of any romantic attachments.
EMAIL [ C ]

B2 a computer file that is sent together with an email message:

I wasn't able to open that attachment.
EQUIPMENT [ C ]

B2 an extra part that can be added to a piece of equipment:

There's a special attachment for cleaning in the corners.

(Definition of “attachment” from the Cambridge Learner's Dictionary © Cambridge University Press)