Entrainment (physical geography) explained

In physical geography, entrainment is the process by which surface sediment is incorporated into a fluid flow (such as air, water or even ice) as part of the operation of erosion.^[1]

References

1. Thomas,D.S.G. and Goudie, A. (Eds.), The Dictionary of Physical Geography (3rd edition), Blackwell Publishers, Great Britain, 2000