Dictionary:

diapedesis

  (dī'ə-pĭ-dē'sĭs)

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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.]

Passage of cells through intact vessel walls into tissue spaces. It is a feature of inflammation.

The movement or passage of blood cells, especially white blood cells, through intact capillary walls into surrounding body tissue. Also called migration.

The outward passage of blood cells through intact vessel walls.

The noun has one meaning:

Meaning #1: passage of blood cells (especially white blood cells) through intact capillary walls and into the surrounding tissue