The term 'shaky start' can be summarized by two crossword solutions: ESS (3 letters) and SEISMO (6 letters). ESS stands for 'Earth System Science', which is a field of study that focuses on the interactions between the Earth's physical, chemical, and biological processes. SEISMO is short for 'seismology', which is the scientific study of earthquakes and seismic waves. Both of these terms are related to the concept of a 'shaky start' as they both involve the study of natural phenomena that can cause instability.