diapedesis
noun
di·a·pe·de·sis ˌdī-ə-pə-ˈdē-səs 
plural diapedeses ˌdī-ə-pə-ˈdē-ˌsēz
: the passage of blood cells through capillary walls into the tissues
Word History
Etymology
New Latin, from Greek diapēdēsis, literally, act of leaping through, from diapēdan to leap through, from dia- + pēdan to leap
First Known Use
1625, in the meaning defined above
Medical Definition
diapedesis
noun
di·a·pe·de·sis ˌdī-ə-pə-ˈdē-səs
plural diapedeses -ˌsēz
: the passage of blood cells through capillary walls into the tissues
called also emigration