Leaving now the verbs derived from vĕrtĕre through prefixation, we find that English and Spanish have a few more cognate words derived from Latin words that contained the roots vert‑ or vers‑. The words Eng. vertex [ˈvɜɹ.təks] (plural: vertices [ˈvɜɹ.tɪ.siz]) and Sp. vértice [ˈbeɾ.t̪i.θe] are technical words referring primarily to ‘the highest point or top of something’ or ‘a point where two lines meet to form an angle, especially the point of a triangle or cone opposite the base’ (OALD), although it also has a few more technical uses in optics and graph theory, for example.
These words come from Latin word that is vertex in the nominative case, the source of the English word, and verticem in the accusative case (vert+ĭc+em), the source of the Spanish word and of the plural of the English word (vertices). (English also borrowed the singular vertice in the 17th century but that form is now obsolete. Also, vortexes .) This Latin word originally meant ‘turning movement, whirlpool’ and it came to also mean ‘highest point, top’ as well as ‘point around which the sky revolves’. The regular stem of Lat. vertex was vertic‑, as we have seen, which indicates that this noun was derived from the root vert‑ by the addition of a suffix-like morpheme ‑ĭc‑.
The Spanish word vértice is used primarily in geometry to refer to the point where the two sides of an angle or polygon meet, or the most elevated part of something (Eng. apex), among other things. In anatomy, vértice refers to the topmost part of a human head (Eng. crown).
Latin vertex had an archaic variant with an o, namely vortex (accusative vorticem), which also meant ‘whirlpool’. This word has given us the learned Eng. vortex [ˈvɔɹ.təks] (plural: vortices or vortexes) and Sp. vórtice, both of which refer to ‘a whirling mass, especially a whirlpool or whirlwind’ (COED), a technical term that became popular in the US in the winter of 2014 due to continuous references in the media to a polar vortex responsible for the unusually cold temperatures. The word vertex was first seen in English in the 16th century and the word vortex in the 17th century. Spanish vértice and the rarer vórtice seem to have entered the language in the 18th century.
The words that we just saw are not very common in English and Spanish, but the descendants of a Latin adjective derived from the noun vertex are indeed very common. The cognates are Eng. vertical [ˈvɜɹ.tɪ.kəl] and Sp. vertical [beɾ.t̪i.ˈkal], and they come from the Late Latin adjective verticālis (verticālem in the accusative case), which is an adjectival form of Lat. vertex, formed with the adjective making suffix ‑āl‑ attached to the regular stem vertĭc‑ (vertĭc+āl+is). The original meaning of the word in Latin would have been ‘whirling’, but in Late Latin it meant something like ‘overhead’. English borrowed this word either from French or directly from Latin in the 16th century with the meaning of ‘of or at the vertex’ and ‘directly overhead’ (French vertical is also from the 16th century). In Spanish, vertical is first attested in the 17th century. The sense of ‘straight up and down’ which this word has now, in both languages, first appeared in English in the early 19th century.