say it: VUR-teks
vertex is a noun meaning "the point of intersection of lines or the point opposite the base of a figure". It carries 2 recorded senses.
the point of intersection of lines or the point opposite the base of a figure
the highest point (of something)
“at the peak of the pyramid”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for vertex come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.