say it: VEE-nuh
vena is a noun meaning "a blood vessel that carries blood from the capillaries toward the heart". It carries one recorded sense.
a blood vessel that carries blood from the capillaries toward the heart
“all veins except the pulmonary vein carry unaerated blood”
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 vena 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.