› to make something less in size, amount, degree, importance, or price: A low-fat diet can reduce the risk of heart disease. Grunn employs 17,900 people, but that number will be reduced by 500 workers. All electronic equipment in the store has been reduced (= lowered in price). › To reduce someone or something to a particular state is to cause that person or thing to be in that state: Without any information, we’ve been reduced to guessing what happened. The town was reduced to rubble in the fighting.