JOIN › to join or fix one thing to another: She attached a photograph to her letter.
attach importance/value, etc to sb/sth › to think that someone or something has importance/value, etc: You attach too much importance to money.
INCLUDE › to include something as part of something else: There were too many conditions attached to the deal. → See also no strings (attached)
COMPUTER › to add an attachment (= computer file) to an email message