
This term describes wine which is held in a bonded warehouse, which has not passed through customs in order to officially enter the UK and consequently has not been subject to duty or value added tax (VAT). Once purchased en primeur (usually in case quantities only, although some traders have taken to selling six-packs), wine may be held 'in bond'....
Found on 
http://www.encyclo.co.uk/local/21497

composed mainly or entirely of headers (opposed to outbond).
Found on 
https://www.infoplease.com/dictionary/inbond
  No exact match found.