the GNU version of the Collaborative International Dictionary of English
v. To convert into a forest.
The Century Dictionary and Cyclopedia
To convert, as bare or cultivated land, into forest, as was done by the first Norman kings in England, for the purpose of providing themselves with hunting-grounds.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
v. establish a forest on previously unforested land
Word Usage
"A program to afforest denuded or severely eroded land has resulted in the planting of about one million trees in 70 areas subject to soil erosion."