ANGIOGENESIS

n. formation of blood vessels, development of blood vessels

Angiogenesis is a physiological process involving the growth of new blood vessels from pre-existing vessels. Though there has been some debate over this, vasculogenesis is the term used for spontaneous blood-vessel formation, and intussusception is the term for new blood vessel formation by splitting off existing ones.
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Angiogenesis /an·gio·gen·e·sis/ vasculogenesis ; development of blood vessels either in the embryo or in the form of neovascularization or [more]Angiogenesis - Community and Resources

Noun
1. the formation of new blood vessels
(hypernym) growth, growing, maturation, development, ontogeny, ontogenesis

[an-gee-o-GEN-eh-sis]
Blood vessel formation. Tumor angiogenesis is the growth of blood vessels from surrounding tissue to a solid tumor. This is caused by the release of chemicals by the tumor.