attachment

noun

• The act or process of (physically or figuratively) attaching.
• A strong bonding with or fondness for someone or something.

  "I have such an attachment towards my fiancé!"

• A dependence, especially a strong one.
• A device attached to a piece of equipment or a tool.
• The means by which something is physically attached.
• A file sent along with an email.
• Taking a person's property to satisfy a court-ordered debt.

  "attachment of earnings"

• The act or process by which any (downward) leader connects to any available (upward) streamer in a lightning flash.

  "2009, Jakke Mäkelä, Eero Karvinen, Niko Porjo, Antti Mäkelä and Tapio Tuomi, Attachment of Natural Lightning Flashes to Trees: Preliminary Statistical Characteristics, published in the Journal of Lightning Research, volume 1"