The term 'kind of approval' can be summarized by two crossword solutions: TACIT (5 letters) and FDA (3 letters). TACIT approval is an unspoken agreement or understanding, usually based on mutual trust. It is often used in situations where a formal agreement is not necessary or possible. The FDA, or Food and Drug Administration, is a federal agency responsible for protecting public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products, and medical devices. The FDA also regulates the manufacture, marketing, and distribution of food and dietary supplements.