The crossword solution for the term 'unlikely to explode' is 'STOIC'. The term 'STOIC' is derived from the ancient Greek school of philosophy known as Stoicism. This school of thought taught that one should be indifferent to pleasure and pain, and remain emotionally stable in the face of adversity. This is why the term 'STOIC' is often used to describe someone who is unlikely to explode or become overly emotional in a difficult situation.