lignify
definition
to become woody or hardened by the deposition of lignin
example
As the plant matured, its stems began to lignify, providing the necessary support for the growing leaves and flowers.
synonyms
hardensolidifywoodify
word origin — The word 'lignify' originates from the Latin 'lignum', meaning 'wood', combined with the suffix '-fy', which means 'to make' or 'to become'.