The term 'become inseparable' can be summarized by two crossword solutions: MELD (4 letters) and eng (3 letters). MELD is a verb meaning to mix or blend together, while eng is an abbreviation of the verb engage, which means to occupy oneself or become involved in something. Therefore, the phrase 'become inseparable' can be interpreted as two entities blending together or becoming involved in each other's lives.