make hard or harder
indurate - harden
The word ‘indurate’ can be used in a literal or figurative sense. Literally, it refers to something that has physically solidified or hardened to a significant degree so that it is no longer flexible or easily breached. Figuratively, it can be used to express somebody becoming tougher, callous, or unfeeling, or something that has become more difficult or intractable.
The dispute between the two nations has become more indurate over time, leaving many to believe that the conflict will soon descend into all-out war.
Chris was indurated by his difficult upbringing, and credits that with giving him the toughness needed to succeed in business.
Progress at the archaeological site was significantly delayed due to difficulty breaking through the indurated clay soil.