It is an anglicised version of the Latin justus, meaning, as one might guess, "just", "fair", "equitable", "lawful", "proper".

BBC: A serious Justin at last

Over lunch at the Justus Lipsius building, the 27 EU heads of government were due to hold an emergency debate on north Africa.

ECONOMIST: Charlemagne

She added that the Justus Lipsius building, where meetings are now held, was never intended for its current use, because in the past European summits used to be held in a range of European cities, not just Brussels.

BBC: Cameron hits out at multi-million pound new EU building