di·a·pe·de·sis 
(dī′ə-pĭ-dēsĭs)
(dī′ə-pĭ-dēsĭs)n. pl. di·a·pe·de·ses (-sēz)
The movement or passage of blood cells, especially white blood cells, through intact capillary walls into surrounding body tissue.
[Greek diapēdēsis, transudation, from diapēdān, to ooze through : dia-, dia- + pēdān, to leap, throb; see ped- in the Appendix of Indo-European roots.]
di′a·pe·detic (-dĕtĭk) adj.