lo ‧ cus /ˈləʊkəs $ ˈloʊsaɪ, -ki/ BrE AmE noun ( plural loci /ˈləʊsaɪ $ ˈloʊ-/) [countable] formal
[ Date: 1700-1800 ; Language: Latin ; Origin: 'place' ]
the place where something is particularly known to exist, or which is the centre of something
locus of
The Politburo was the locus of all power in the Soviet Union.