Meaning

adjective relating to or based on the number twenty

originFrom Latin vīgēsimus (“twentieth”), variant of Latin vīcēsimus (“twentieth”), from Latin vīgintī (“twenty”), (from *vīcēnssos, from Proto-Indo-European *wi(h₁)ḱm̥ttós, with the -imus ending of decimus (“tenth”)) + -al (suffix forming an adjective). Compare Latin vīgintī (“twenty”), from Proto-Indo-European *h₁wih₁ḱm̥ti, from *dwi(h₁)dḱm̥ti(h₁), *dwi(h₁)dḱm̥ti (“two tens; two decades”).

Etymology from Wiktionary, CC BY-SA 3.0