The crossword solution for the term DON'T BLOW IT is FUSE, which is a four-letter word. FUSE is an electrical device that is designed to protect an electrical circuit from damage caused by excess current. It works by melting and breaking the circuit when the current exceeds a certain level. Therefore, the phrase DON'T BLOW IT can be interpreted as a warning not to overload the circuit with too much current, as this could cause it to blow.