The term LEAD-IN TO -STAT can be solved by two crossword solutions: THERMO (6 letters) and AERO (4 letters). Thermo is a prefix derived from the Greek word 'thermos' meaning heat, and is used to refer to heat-related concepts such as thermodynamics and thermochemistry. Aero is a prefix derived from the Greek word 'aer' meaning air, and is used to refer to air-related concepts such as aerodynamics and aeronautics. Both of these prefixes are commonly used in scientific terms to refer to the study of their respective elements.