The term ACORN PRODUCT can be solved by the three-letter word OAK. OAK is a type of tree that is native to many parts of the world, including North America, Europe, and parts of Asia. It is known for its strong wood and acorns, which are edible nuts that are produced by the tree. Acorns are a popular food source for many animals, and they are also used in some human foods, such as flour and bread. Acorn products, such as acorn flour, are becoming increasingly popular as a healthy alternative to traditional wheat flour.