To make something resistant to a particular effect or condition. They proofed the deck so that it would resist rot and insects.
To read and correct a piece of written or printed material. She proofed the article for any grammatical mistakes before it was published.
To activate yeast by mixing it with water and sugar to start fermentation. Before baking, you need to proof the yeast to ensure it is active.
(intransitive) To rise as a result of fermentation, said of bread dough. The dough needs to proof for at least an hour before baking.