Verb:

कठोर बनना, कड़ा बनाना, कठोर करना, ठोस करना, ठोस बनाना,

stiffens's Usage Examples:

Let the cake sit for a few minutes so that the buttercream stiffens.

When pieces get covered in rust it stiffens up the joints and can cause a lot of damage.

Simple roofs in general use with a double slope are the " coupled rafter roofs," the rafters meeting at the highest point upon a horizontal ridge-piece which stiffens the framework and gives a level ridge-line.

The joists are covered with a waterproof material such as asphalt, lead, zinc or copper, the three last materials being usually laid upon boarding, which stiffens the structure and forms a good surface to fix the weatherproof covering upon.

Synonyms:

change, rigidify,

Antonyms:

derestrict, stay, loosen,