lignify

verb (used with object), lig·ni·fied, lig·ni·fy·ing.

1. to convert into wood; cause to become woody.

verb (used without object), lig·ni·fied, lig·ni·fy·ing.

2. to become wood or woody.

verb -fies, -fying or -fied

1. botany to make or become woody as a result of the deposition of lignin in the cell walls

1. To make or become stiffer and stronger by the deposition of lignin.