ver ‧ tex /ˈvɜːteks $ ˈvɜːr-/ BrE AmE noun ( plural vertices /-təsiːz, -tɪsiːz/ or vertexes ) [countable] technical
[ Date: 1500-1600 ; Language: Latin ; Origin: vertex , vortex 'turning movement, whirlpool, top of the head, top' , from vertere ; ⇨ ↑ verse ]
the point where two lines meet to form an angle, especially the point of a ↑ triangle