The term BE ECONOMICAL WITH can be summarized by two crossword solutions: REUSE (5 letters) and EKE (3 letters). REUSE means to use something again, while EKE means to make something last longer. Both of these words are related to the idea of being economical with resources, which is the idea of using resources sparingly and efficiently. This concept is important in many aspects of life, from environmental conservation to personal finance.